Could my daughter be developing diabetes?

I have a 9 year old daughter who has been unwell on and off for about a month and hasn't managed a full week at school for 3 weeks. She started having panic attacks and for the last 3 weeks she's been feeling sick but with no actual sickness or temp. I realised yesterday as we were playing a board game together that she was drinking almost constantly and was going to the toilet alot (not really a surprise with the amount she was drinking!) and mentioned it to my husband later that evening.

My husband has type 2 diabetes and suggested I test her sugar levels which I did. They showed 7.2 which I wasn't too worried about but I tested her again this morning just to put my mind at rest and it showed 2.9 at which point I did panic a bit and took her to see the doctor. Stupidly, I gave her a bottle of juice to take with her which she kept drinking from and when the nurse tested her it showed 4.4 which is in normal levels. The doctor told me she doesn't have diabetes and he thinks all of her symptoms are down to stress and her drinking alot has become habitual and she's using it like a security blanket.

However, i've just tested her again and her sugar levels were at 7.9 which isn't really, really high but i still can't quite relax about it. My husband was only diagnosed just over a year ago and she's showing some of the other symptoms that he had too, she has dry skin and she keeps complaining that her eyes keep going blurry. I'm actually really worried about her, does anyone recognise what i've said or am I just over reacting and should just trust the doctor? I would really appreciate anyones advice x

The reading I took this morning was taken as soon as I got up this morning so she hadn't had her breakfast yet. The second test that I did was done about and hour and a half after she had eaten. I have spoken at length with her over the past few weeks about if anything is worrying her but she say's that there's nothing she can think of. However, my stepdaughter moved in with us in February because her mother is an alcoholic and we are currently going through court to keep her with us. I have spoken to Lorna (my daughter) about this and she was adament that she isn't worried about it but I have wondered if it's worrying her more than she realises. The doctor suggested getting in contact with the health visitor to see if they could recommend a support group for her which I think I will do on Monday. Thank you for your help, I think it's one of those times when having a little bit of knowledge has been a bad thing and I feel so bad that she's so young and yet seems to be so worked up! Thank you again for your advice, it's much appreciated x