are you talking to her alot about the baby? She probably wouldn't really get it, at 17 weeks it's probably not that obvious, so if you keep brining it up maybe she's confused. DD was around 18 months when I found out I was pg and we didn't really start talking about until about 2 months before DS came.
My DD will be 3 in March and sounds very similar to your DD. She's in a bed and about 1/2 the nights I'm either in her bed or she's in mine half way through the night. She also climbs onto my chair during dinner. If it's bothering me I tell her if she's done eating she can watch tv or color or something. She lets DH do very little. He does bath and bed, but many nights she refuses to let him put her in the tub, I'll put her in and then she's good to go. Other than the purposely peeing thing, which I don't know what to tell you, that would really bother me too, my DD sounds very similar to yours, I try to let alot of things go which seems to make DD and I more relaxed. DH gets upset with me and her alot, but I feel like if her or anyone else is not in danger, why make a big deal of it.