OK Personally I don't believe in the whole alpha thing in the sense of the "higher" vs. "lower" Now, if your dog isn't letting YOU sleep in the bed or guarding it, that is a different problem. If your dog happily moves over when you lie down you don't really have an issue. Anyway, I can understand how sleeping with them might be a problem. Mine are hot so they are sleeping on the floor right now but by morning Sam will be on my pillow and Loki will be cuddled up next to me. My husband loves them but does not want them next to him because they are hot so he just moves them over by me when they get too close and 90% of the time they sleep by me. Loki actually has a "move" command but Loki is brilliant.
Anyway, here's how you do it. First, get her a REALLY comfy bed. My dogs LOVE their beds so they don't mind sleeping in them. Then, every time she gets on the bed just say "off" and set her back down on the floor. Once you do this 20 times she should start to get it.
As far as the housetraining thing, we have a tell bell upstairs in the bedroom and we close our bedroom door. Sammy wakes up super early and needs to pee right away so she will hop off and frantically ring her bell to wake us up. Loki just sits on my head and stares at me until I get up
The other thing you can do is put her in a crate (it's not that bad.. Sammy is sleeping in her crate right now - on a HUGE fluffy pillow - and she will probably sleep there most of the night...) and she will bark or otherwise wake you up when she needs to go out.
BTW Sammy was 1 year old and not housetrained at all and she figured out the bell. It's pretty easy for most dogs because it's an immediate gratification thing. If they ring the bell they get attention, and they get what they want. The first time they do it I swear a lightbulb goes off and they are like, WOW COOL! Ding ding ding ding...ding ding..dingdingding......