I am your age and I also have a 2 year old daughter and 7 year old son. They both sleep in their own beds, although my daughter wakes up sometimes in the middle of the night. I go to her room and crack the door. I never take her out of her room, it just makes it worse with her thinking I am taking her to my bed. She has security items she has to sleep with everynight or she won't even lay down. I have a teddy bear that is fuzzy white and lights up the whole bear with a red, blue and green lights that alternate. Also acts as a night light. and then she has her baby. This is one baby that never leaves her bed. She has ton's of babies but this one is her night night baby. She knows when she is holding baby its time to go to sleep. My number one thing is do whatever you can to get her to sleep rock her, pat her back, stay with her til she falls asleep but don't take her out of the room to your's. It took me a long time of sleepless nights getting her used to her own room w/ out me but she is used to it now and usually just wakes up if she is thirsty or cold or hot. I hope this helps. Remember the hard work and no sleep will pay off and you'll finally have your bed and full night sleep!!!!!
Also your six year old is big enough to understand and follow rules. I make consequences. even though they are not strick but they work. His favorite toy or game or if he likes watching tv. If he doesn't go to bed and stays up and doesn't go to bed like he is told I warn him w/ one of these things and if he doesnt' listen the next day I will have the tv off limits for him and he has to find something else to do and play with. It generally works b/c he doesn't like being able to not watch tv or play his video games. He understand if he doesn't listen he doesn't do get to do what he wants afterschool. It is okay to sleep on the couch on wknds, but during the schoolweek it is enforced.
I hope this helps. Just put your little girl to bed repeatedly over and over it will eventually work. and set rules and boundaries for your son. make him understand he is a big boy now and has big boy rules not baby rules anymore. just work with them on their level!
Let me know if you agree or disagree and if it helps!
~A. R.