Just normal pre teen or due to new partner?

[Lovemusic33]

I have 2 dd's, dd1 is almost 12, started her periods back in the summer and is pretty hormonal at times.

I split from their dad a year ago so it has just been me and the dd's for a little while so they have had my full attention. I now have a new partner who the dd's seem to like ( as far as I can tell and going by what they tell me ). Dd1 has been spending a lot more time on her own in her room or with dd2 in her room and I rarely see her anymore, she will come home from school and go up to her room, pop down for dinner and then go back up, she will come and spend half an hour downstairs before she goes to bed. Is this normal pre teen behaviour? I am worried that she feels pushed out by my new partner although he goes out of his way to make sure the girls are happy and puts the effort in to communicate with them.

I feel a bit guilty as it must be a huge change for them having someone new around ( in their home ) when it has just been me and them for a while.

[Lovemusic33]

It's not just when my new partner is here. She came down last night and watched a bit of to with us , I guess she's just growing up and doesn't need to be around me as much.

[Andro]

Vanishing preteen is quite normal, but if you're at all concerned then some mum/dd1 time and a chat might be in order (car convo is great if she can be a reluctant talker or at home with a 'treat' drink/cake if she's easy to communicate with).

Does she only vanish when your partner is there or doesn't it matter?