WIBTA For Moving Out Despite My Roommate Being Pregnant?

All Names will be changed for convenience/Privacy. Even though my roommates dont use reddit.

So me and my partners, live with Dan and her fiance, as well as their 4 year old daughter. I tend to help with their daughter, since the two work mostly nights and need the assistance since Dan is currently pregnant. However, my partners and I have begun to notice how much we spend on the household compared to them, as well as how much we clean and provide child care at no cost to them. Ordinarily this wouldn't be a problem, however we're spending well over $1,700 on just rent and food alone (they fly through all the food I ever buy) which leaves us with practically no money for ourselves, and now me and my partners are looking for a new place to move to, since it's beginning to feel like we're being used.

However, this leaves Dan in a compromising position. And I would like to know WIBTAH for moving out and leaving them to fend for themselves because of how we've been treated?