You need to spice up the relationship. You need to change where you make love, how you make love, and when you make love. You need to make an effort and work on the passion and excitement. If you do those things, you wouldn't have to change your partner. Once you pass the honeyMOAN stage, which is after the first 6 months, you have to plan for it.
Romance needs to be intentional.
My daughter is involved in an online relationship with another guy. Their discussions have gotten pretty hot and heavy. Hopefully they are young. If a child is too young to have sex yet, then it's a way to sublimate it without acting it out. She should have family members around if and when she meets him.