Typical layouts have a full bathroom attached to the master bedroom, with another full bathroom elsewhere accessible through a common area, and ideally another half bathroom somewhere also accessible through a common area.
That allows the parents to have their own shower/tub, and the children to share a bathroom with a shower/tub, and the halfbath would be kept presentable for guests to use and wash up in. But usually two full baths is enough for a family of 4-5. Four is way overkill.
Nazis