Does she have a crush on me?

Hi all

I am a young single guy currently working in a lab (about 4 months) with a dozen of scientists. Among them, there is a single, and really beautiful girl (my colleague) who ignored me (kinda rudely) the most at first, and I did the same to her to return the favor as nicely as possible, no hello, no even a smile. I'm not sure when and how it started; maybe once upon a soft argument we had over a safety protocol, but anyway, now it's a couple of weeks that I've noticed she's apparently showing subtle interest to know more about me. Her demeanor has turned friendly, is very up and ready to say hello and greet me, and she usually tries to ask me kinda personal questions during our working conversations. She doesn't consume all her coupons in a single day, instead, she usually asks me a single or two personal questions in a day when at work and only when we're alone. She seems to know what she's doing, but I'm not sure what she intends to convey to me. Here are some attempts she did to extract info out of my life:

1) Asking about my age
2) Telling me her own age while I never asked because I know it may look rude to girls and women. We now know she's one year younger than me.
3) Asking about my previous posts and occupation before starting my job here.
4) Offering me her number for working reasons and asking for mine as well while I never asked for a phone number exchange. (of course, this one went so bad and awkward. Don't blame me. I myself even don't know what happened, I just know none of us have each other's number yet, at least me.)
5) Asking me if I'm single.
6) Asking me about my plans for the future.
7) etc.

Can such behavior mean that she has a crush on me or is evaluating me for marriage maybe?

My guts tell me neither to take her seriously nor to bother my life with a stupid love story; however, honestly, I like her, but still doubt whether she's into me or it's just my foolish imagination since I've caught her a couple of times talking and joking with other colleagues, too. I felt jealous when she looked at me and kept sharing words and smiles with others, but no reaction/attention was sent to her from my side for the sake of my attitude. I never ever want to look rude or freak. Just help me understand this bizarre creature.