I am on a well that is shared with my mom next door. We have plenty of gpm and it only happens after a rain. I am guessing it has to do with a clogged filter or something but I'm not sure where it would be located to clean it.

Rain shouldn't interfere with your water pressure. Do both of you lose pressure or just one of you?
Describe your filter system. Does the pump pump up to pressure but it doesn't reach the houses?
Does the pump work but no pressure at all?
More details please. Tom

The pump is under my mobile home and is also piped to my mother's next door and there is a slight incline to her home. The pipes are underground. The pressure gauge on the pump reads 90 psi right now but right now our water pressure is good, I'm not sure if it reads the same after a rain. She loses more pressure then I do and for longer but it never goes completely out.