Their bossy and they can move anywhere they want! Unless you block it with pwps or have houses around, or else they can even be in front of your bridge (Paula did that to me but luckily I am resetting her plot)
I'm trying to get Chrissy next to Francine's house and she is being so stubborn i've been doing this for an hour or so and last night i did it for about 2 hours. ITS SO FRUSTRATING