People hate to admit, but Valerie is a second option for Judy, I'm not saying she didn't develop feeling for her eventually, and ended in a more meaningful healthier relationship with Valerie, but fact is, Judy was way too obsessed with Evelyn to let it go, to see anybody else.
Now this is not a problem for Vincent because of obvious reasons, so he plays the role of an elder brother for Judy, a shoulder for her to cry on, and someone who she can rely on for anything, always. Which in my opinion just fits so much more in the context.