Almost 2 year old NOT SLEEPING

So this question is for a friend not for myself, but i thought i would get some other people's opinion.

Her little girl is going to be 2 in August i will call her Miss A, she has always had trouble with her sleeping, but lately it is taking a toll on their family. Miss A wakes about every two to three hours at night, Almost NEVER sleeps through the night, they did the control crying thing so she now self settles to go to bed which they have done since she was about 4 months old. When she wakes up at night it is really hard to settle her and most of the time she ends up in their bed. Even during the day she only sleeps for about 30minutes all day!!!!! They have tried almost everything nothing seems to work. They are going to take her to a sleep school but i thought if anyone has any ideas that might help before they go would be great.
Could she have some sort of sleep disorder???
I dont know much about sleep disorders just thought i would ask

Thanks in advance

Our daughter was exactly like that, woke a lot at night, short sleeps during the day. We eventually worked out she just didn't need that much sleep. We also would bring her to bed with us at about midnight and if she stirred one of us would just rub her back or tummy till she slept again. It was the best thing we could have done. In stead of fighting to get her to sleep more, we just adjusted our lives.

Now she is 5.5 and goes to sleep at 7.30 ish and gets up at 6ish and entertains herself with animals and toys til we get up at 7. She still does wake occasionally and we just co-sleep or put her back in her bed, depending on how we feel. (sometimes we just want cuddles!)

HTH