Well, you have to tell her it's time for a serious conversation, and sit down with no distractions and discuss this.
You need to tell her you have sexual needs and that it is expected that in a committed relationship, both spouses will strive to keep the other satisfied. Ask her point blank if she still loves you, and if she still feels sexually attracted to you. Ask her if SHE has a problem with how she sees herself.
If she is unwilling, you may need to start considering whether this is something that may end the relationship. She may be immature, or think that now that you are a father, all you are good for is to bring money and care for her. If she is that selfish, plan on divorcing.