When you fill the pump basket and fire the pump does it drain the basket quickly as it normally would do? That would indicate the impeller is OK and it is pumping. If it does pump then the next thought is an air leak somewhere on the suction side. Any sign of overheating on the basket lid or pipe fittings at the pump? Normally overheating of the basket area would occur when the output is blocked and you're just churning water in the basket and getting the water hot. That could warp things. Really sounds like an air leak though and it could be a hairline crack somewhere. Doesn't take much of a leak to prevent priming. Did your sister have to open the basket lid for any reason while you were gone? Look at the basket lid first then valves and finally the piping and bonded joints. You really won't know until you get it pumping at pressure if the seal has been damaged by running dry for those time periods.
Best I can do for now and wishes for a speedy recovery.
Al
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