A bunny that hits puberty often gets grumpy, nippy, territorial and doesn’t like to be held. It seems to be especially true of girl buns. It’s perfectly normal, not cause for alarm.
It is also very typical that a pet is very subdued the first days in a new place – I would think it’s because it’s wise not to be too cocky in unknown environments. (Of course a bunny doesn’t know what’s wise and un-wise, so it’s an instinct, not a thought-out plan). Once the new pets starts to feel at home, it feels comfortable enough to “be itself”. That’s a good thing, it means she’s getting settled in.

If she starts pulling fur off of her chest and tries to make a nest, it might be a sign that she’s pregnant – but it might also be a false pregnancy. You will of course find out sooner or later. If she’s having babies, she’ll need a nest-box and you will probably have to assist her some with the babies because a first time mum can become a bit bewildered by the whole situation. (Not surprisingly!)

It’s very wise of you to keep the two buns separate until they can be de-sexed. A month or so after the desexibng you can start bonding them (a boy bunny can have live sperm for 3 weeks a month after he’s been neutered.)

New bun owner advice that I can think of right now is lots of grassy hay 24/7, a hidey-box made out of a cardboard box, preferably with two exits so the bun doesn’t feel trapped but knows it has a safe hiding place in case it needs one. I’m sure others will have lots of other tips for you!

And of course we’ll want to see pic of your buns, but it can wait. No need to stress them out by taking pics just now =)

I agree with everything Bam said. You bunny sounds very normal to me.