Idk if it's pregnancy hormones or not but every time I go over to pick my sons up form my moms we…

Idk if it's pregnancy hormones or not but every time I go over to pick my sons up form my moms we always fight. I asked her to start buying 4t-5t pull ups for my sons because the 3t-4t were getting too small and she goes I'm not buying a bigger size you get less in a pack. And after we argue a bit she goes your always so ungrateful I should have never thrown this baby shower for you. And I said you didn't have too. I never asked her too she says she said that she and my sister did it because we are family and I was like but you didn't have too. Every time we argue she always says how she shouldn't have done the baby shower because it's too much money and that I'm always ungrateful. I'm so stressed with her like I wish I didn't have to have her as a babysitter sometimes because she is always yelling at everybody... there's more to the story but I just wanted to vent because my boyfriend doesn't want to hear it!