Hi there,
So sorry to hear your DD is having such a tough time of it!
I too had pretty bad skin, I was a bit older - about 17 but it then turned to adult acne.
I have been on Roaccutane also - I only saw an improvement after I stopped it - this can be common. However, while I totally agree it is a last ditch attempt, I know a number of people who have been on it and the side effects have been limited - drier skin (treatable with moisturiser) and dry lips (always used Carmex to help) - so I would recommend it rather than the torture that is extreme acne! Only you and your daughter can know wether it is right for her! Also - please don't take my word on it, there are plenty of site which chat about it!
Anyway - that was a slight tangent! I would firstly recommend getting a good, understanding Dr on side, acne is a try/test issue and if your Dr is good and willing to listen and test things then it is half the battle! Posssibly request a referal to Derm as early as you think - appts can take a while!
RE: Dianette - I would certainly try this before Roacc (you also have to be on birth control to take Roacc so either way it helps!) I read up on & spoke to my GP about the 'weight effect' of BC pills inc Diannete and found that it can often be a placebo effect - or it can increase cravings, however if you monitor your diet (which by the sounds of your daughter she does) then you can limit any weight increase on Diannette as it is not the full pill. Also - I consoled myself with the fact that if I did notice a weight increase I could stop.
What I would seriously, higly recommend though - is to moniter her diet! I was recommended recently to cut out milk from my diet as this can heavily increase the acne. I cannot tell you the difference this has made! I drank quite a lot of milk also, so that would explain the huge improovement. I also try to limit my cheese/ yogurt intake too - but I believe milk has made the biggest difference! I have 2 friends who also have skin problems and I mentioned cutting out dairy to them and they have both tried it - and both have also seen a big improvement!
Also if you said she is worried about putting on weight she may not be eating very well and it could be something in the way she's eating causing the acne to flare up!
This may not work - and is obviously anecdotal but it is surely worth a try! I believe it is recommended to give it up for 4 weeks, amd you should see an improvement by then if it will work at all!
I'm sorry this is so rambled- I am at work but just wanted to share my experience!
One more thing - if her confidence is taking a knock - why not take her into a store with a make up department and explain to them the problem (MAC or Estee Lauder are usually best) and let them try some stuff on her, concealer/ foundation etc. I always find they work miracles and it may make her feel much better and means she will have the make up for 'feeling rubbish days'. My Mom did this with me and it was a great day and I was so happy. Obviously this is budget dependent, just thought I'd suggest it!
I do hope this has helped - if not feel free to ignore!