Trouble with a capitol T

As I have mentioned here before we have a patience challenging daughter who is 3 and cute but I am starting to run out of patience.
Forever-like a year-she has been making her way into our bed and we just make room and she goes back to sleep. This used to occur at about 3:30am. Now the back story is that I am just getting to bed at 1am and barely able to acknowledge her entrance 2 hrs later.
In the last few nights she has moved this up to 2-3-4 times a night, she is up and asking for a drink. The last two nights she actually decided to go back to her own bed at about 6am. Gee Thanks your sister is up in an hour dressing herself and turning on the TV.
I have asked for ideas in the past but some are difficult to try as she shares a room with her sister who is also sleeping. Another suggestion was to baby gate her in but she will just stand there and scream (her favorite past time).
I guess I am going to have to battle with her which means I am going to lose the last few precious hours of sleep myself. This usually leads to me being an overtired bitch and so we battle all day too.
I see I have many readers from all over the place so come out of the woodwork Mama's and tell me your ideas. I have already considered Duct Tape but I can't have DSS involved in my life.