Can I first say that you're super awesome? I can, because I just did.
Now that we're done with the flattery... er... admiration section, to business. I kind-of-ish like a girl. Wow, that sentence was hard to write. Anyway, so I like a girl, and we're close friends. I sort of get the feeling sometimes that my feelings may be requited, and I've graduated to pull-ups by now, so I would simply ask her out, except... Well, there are two things stopping me.
One is that I'm not totally sure of her feelings, and I can't really display my own short of asking her out. Why is that, do you ask? Well, because I'm the sort who hugs everything in sight, gives and receives piggy-back rides, we already have regular conversations, similar activities, all that jazz. So it's hard to gauge interest. Sure, she treats me differently, but we're really close friends, so she would treat me differently.
I know, I know, just go for it then, there's a chance, and what's she going to do, disown you as a friend because you think she's really awesome? Well... I don't know all of the details, but she had a boyfriend before who was part of the group of friends we have. After they split, despite trying to be friends, they couldn't, and the ex ended up leaving/being forced out of our group, which is also kind of ambiguous on details (I wasn't as integrated within this group at that point, so I apologize for my lack of knowledge on this particular point. But that kind of adds to my indecision). So I don't know if I want to risk my other friendships based on this. I just kind of want to know if there's some sort of way to better gauge interest beforehand, or should I just go ahead with it, or should I hold back, or... is there some sort of creative something-or-other that could fix things.
You're awesome. Best, Anon.
There are two issues here: your risk of getting booted out of the group, and your attempt to see how she feels without straight-up asking her out. Stop worrying about the first thing. She's not going to date you, dump you, and then jettison your sad, flailing body out of the group like a hapless ejection seat. I will bet you dollars to donuts that the last guy wound up leaving because the breakup went badly, not just because they had a relationship and it didn't work out. (Note: I own neither dollars nor donuts.)
Trying to keep the same group together when two people have just broken up is awkward, sure, but it's not some unsalvageable mess. People only get forcibly bounced when the thing was a disaster or one person can't let it go. I personally dated a girl who remained good friends with every ex she had, one of whom was in our group, and apparently everybody was fine with this. It's completely doable, and you will not be exiled to live alone in a cave on the moon.
You know how that relationship started? This question is only partly rhetorical, because I don't. We were in your situation—good friends who teased each other and hugged all the time and stuff, and then one day I did a double-take and went BWAAH? because I realized that we were somehow dating. In situations like this, with mutual interest, the shift in behavior is subtle, but it's there; you just need to know what to look for.
I realize that you two are already all huggy and stuff, but surely you have a baseline level of hugginess and you would notice if she became even huggier than she had been (and to anybody who isn't already touchy with a potential love interest, and that love interest is hugging you all the time, then yes, (s)he likes you). If she's suddenly twice as physical with you as she was before, either she likes you or has grown extra arms. If she's picking lint off your sweater, she likes you. There is no lint. There is never any lint.
People who spend time around you tend to behave more like you—you've probably noticed yourself adopting some mannerisms or expressions from this group of friends. But in a more direct way, people who shrug when you shrug, or remove their pants when you remove your pants, are probably showing attraction. If this girl is mirroring your actions in one-on-one conversations, she's probably into you.
Responding with jealousy
Mention something about another girl (within reason, of course) and pay attention to how she reacts. If you notice a hot girl and comment innocently on her appearance, and your friend goes "PTHHBT" and spit-takes soup everywhere, even though you guys are just standing at the bus stop, be like "Where that that soup even come from? Do you need a doctor??" (But also, be aware that she's only flustered because she wants you to notice her, not random strangers.)
Responding with the complete opposite of jealousy
If, on the other hand, you comment that some random girl is cute, and your friend takes her response way over the top—"I know, oh my God, you two should get married, I would be soooo okay with that"—and is otherwise far too eager in her reaction, she's probably covering for her jealousy with extremely fake unjealousy.
Attempting to provoke jealousy
This is just anecdotal, but several times in my life, girls in my group of friends devolved into lascivious discussion about hot dudes while the guys in the group sat there going "uhhhh" for twenty minutes because they had absolutely nothing to add. In every instance of suspicious hot boy talk, the instigator turned out to like someone who was present. Of course, statistically, this was bound to be true anyway, so do whatever you want with this information.
Being curious about you
I know the two of you are friendly, but friends do stuff like send each other memes of cats stuck in bottles, or gifs of cats falling down stairs, or texts about how funny it is when cats are repeatedly wounded. In my experience, regular friends almost never text each other questions about life and the future and stuff. They're curious about how other friends are doing, but they rarely initiate serious conversations to find out more about you. This is a sign of someone who genuinely cares what you're like.