She just won't sleep

[DeathProof]

My boyfriend has three beautiful girls, the youngest turned 2 in March, and she won't sleep. We try to put her in bed by 7-7:30, but she won't rocking her crib, and making a weird humming sound. She will shout, and talk to her sister (in another room, already sleeping, by the way) till 11 o'clock at night! She may sleep for a few hours, but she's up at anytime at the night, often for hours. There are nights where neither my boyfriend and I, nor Keira (2 year old) get more than ten minutes of sleep. Not only that, but instead of being more inclined to a nap after a sleepless night, she will refuse to take her nap, and it just spirals from there.

She is two, and hasn't slept through the night. I just needs tips and maybe a reason why she just won't sleep.

[margypops]

It could be because she has naps during the day, how long and what time does hse nap to ...some children of 2 dont need a lot of daytime sleep, so its not her fault you cant have it both ways so less sleep during the day may do it make sure she is timulated enough plenty of fresh air and outside activity get her Dad involved having fun getting rid of that surplus energy. No drinks and food too long before sleep at night, put her into her crib /bed and leave her , read some stories to her first ,  then if she yells, let her, dont go in , she will be okay once she knows its not going to work she will go off to sleep, but as I said make sure she is tired...Good Luck