We just curbed that behavior. Problem? She just turned 4. :)
She came in regularly when she was that age, and we had a new baby in the house. We let her so she didn't wake baby and we could have a few more minutes of sleep....since that is all we got then. Minutes of sleep...not hours.
We let it go on and on because baby #2 never slept through the night for over a year, and then we moved and had a huge transition, etc. So, when she turned 4, I told her, "When you turn 4 the rule is, you have to sleep in your own bed all night long!" Of course being older, she wanted to follow the rule. We had to walk her back several times. We always told her how proud we were of her when she slept all night long in HER own bed." We've only had about a total of 60 nights in the past 4 years that we've all slept through the night AND in our OWN beds. (We are tired.)
You need to choose a date (like a long weekend) and committ to keeping her in bed. You take one night, hubby takes the next. Tell her the new rule is....., give her lots of reward and praise for doing it (even if it is only coming in 3 times the first night).
You are right. You need her out of there. You will all sleep so much better. There was a study last fall that showed that kids that slept in the parents bed (at toddler age to elementary age) didn't get the quality sleep they needed and showed symptoms similar to ADD/ADHD during the day. That came out just as I was telling hubby the kiddo had to go! Best of luck to you!!!