How big is the RV that your mom and her husband have? The reason I ask is that some sites allow an RV and a tent. You may want to check to see if you and your mom can share one site with her RV and a popup.Its going to be me and my 3 kids- no spouse or significant other. Then in the RV will be my mom and her husband, and in one of the cabins, my sister, her husband and their three kids.