Definitely try the baby gro-bags! Viznil's spot on with that. I had one for my second, and it was fantastic. So much so that I've saved it for when I'm a granny - I felt it was the best thing I could ever pass on to any future daughter-in-law I had!!
Baby's cosy, she can still move around enough but is too restricted to stand up, you'll never have to get up in the night to tuck blankets back in, the familiarity of getting in it will send her off to sleep content and also, if you go to stay anywhere, she'll have the security of her own bed wherever she is. I can't praise them highly enough!
One thing though, is to buy two-piece pyjamas aswell if you do buy a grobag, because we found it was the best way to regulate temperature. You can have just a vest, plus bag of course, or vest and top, vest and thicker top, or full pjs when it's really cold. You really won't look back! Buy a decent one and you'll get quite a bit of your money back on ebay later, too. (Extra tip!)
Good luck sis!!