Are you obligated to hang out

So my fiancé’s grandma came to visit, and she wanted to know what size he’s in so I tell her thinking nothing of it. I thought she was just trying to have a conversation.

Later on we find out she bought him two outfits for dinner and a box of diapers. My fiancé and I do Uber eats as a way to make quick money to buy diapers for our son. We did Uber eats that night and I was tired. The plan was to go pick up the things his grandmother bought and go home. This is at like eight/ nine at night so I’m not going to want to hang out that late.

Well his grandmother felt some type of way and accused me of not making an effort for her to see my son. We saw her the day after she flew in plus we were seeing them for dinner.

My question is are we obligated to hang out with her just because she chose to go buy stuff for our son? Even though we spent all day Wednesday with her and had dinner with them Friday.

I’m starting to think his family only buys things to make someone hang out with them instead of genuinely giving a gift.

Before someone assumes this: We don’t ask his family for anything. They always ask us if he needs anything or if he’s in a bigger size.