bed time with an 18 month old girl....

my baby girl has always been really good at bed time! we recently moved in with my parents well after a few months i decided it was timr to put her in a big girl bed, first couple nights went great! she shares a room with us. last 2 weeks she has been fighting so hard to get out of her bed.. anyone have any advice on what to do? she keeps getting out and either comes to my bed to lay down with me ( which she knows isnt allowed) or starts to play with her toys on the floor