Awww Kelly- my DD is so much like your DD when i comes to sleep- it was 12.30 the other nite and b/c its school hols and she is not metally tired- most nites it is at least 10.30!!!

My DD is an absolute nightmare to get to sleep- if she starts to get tired early and i miss the opportunity to put her to bed i am a goner and she is up till all hours!!
Things that have worked for me over the years are:

Stroking her head until she goes to sleep- once she loses it- then it is impossible to get her to sleep- stroking her head keeps her calm

An eye mask- sounds freaky i know, but she can still have a light on, but the sensorial stimulation is taken away and more chance to go to sleep

Playing her leapster- these have been fantastic- esp when she is 'not tired' she can play her game in bed quietly by herself for hours and i at least get a break and she gets some quiet time- btw i got her kids headphones with them- they are a gem as well. Also her looking at books tends to make her sleepy as well, and go to sleep with books open!

We ended up taking away after school activites for her for a while until she started going to sleep at a good time. This worked really well for a bit as she wanted to do the activities so she tried that bit harder!

New bedding- a new doona, pillow and underlay that she chose herself made her bed more comfy the way that SHE wanted!!

If i remember right Marissa is going to school this year???? You will notice a big difference then! MY DD his pretty smart for her age as well, and if she doesnt get enough mental stimualation througout the day- she just does not get tired enough to switch off at nite!!!! Their little minds have trouble turning off and its hard to teach them to do so!!

Hang in there- the more you stress, the more she will!! Plus you guys are obviously going through heaps of changes at the moment and she would be picking up on them tooo!

Take care hon and keep sane!!!!!
odette