Yesterday, 03:11 PM
So, it's definitely possible that your mom is overfeeding the baby--it is surprisingly easy to do so. But it's hard to know if that's what is going on here unless we have a better idea of your separation length from your baby. How many total hours are you away from baby? The general rule of thumb is that baby will need somewhere between 1-1.5 oz per hour of separation from mom. For example, if you are away from baby for 10 total hours, you would expect baby to be taking in anywhere from 10-15 oz. during your absence.
Does your mom know about paced bottle feedings? Pacing the feeds is important, because baby is used to feeds taking a little bit more time at the breast. Baby has to work to get milk at the breast, whereas the bottle just drips out easily for him. Baby also is used to getting comfort sucking needs taken care of at the breast, too. Sometimes baby is not crying because he is still hungry, but because he is simply not ready to be done sucking! Here are some guidelines for paced feeding: http://www.kellymom.com/store/freehandouts/bottle_feeding.pdf
Are the bottles she is feeding baby of a reasonable size for a breastfed baby? Generally, you want bottle feedings to be small and frequent, just like nursing. So bottles should generally be no more than 2-4 oz each, and baby should be fed frequently and on cue.
As for the pumping end of things, more information will also help troubleshoot here, too. Again, it would be helpful to know...