Advice! Am I offending my boyfriend’s mom by doing this?

Okay so I’ve been living with my boyfriend and his parents for about 4 months. We plan to move out in about 8 months or less. Anyways, I absolutely love his family. We have our own room and we don’t pay for anything. So we’re able to save a lot. His parents buy groceries and of course if there’s something else I want or occasionally my boyfriend wants in addition we buy ourselves with our money. So really it’s an awesome situation. However I’m having a small issue I need advice on. So my boyfriends mom cooks dinner most nights. If I’m being honest I don’t particularly love her food. I’ll admit I’m a picky eater. I think I hurt her feelings last night because she made vegetable soup and instead I chose to get some tomato bisque soup at Walmart (I was just really craving that). She didn’t say anything but I could tell she was a bit offended and upset. I do try to eat her food, it’s not like I don’t, and always compliment her when I eat it. But I don’t think I should feel guilty about not wanting to eat something I don’t find appetizing. Am I being rude? Idk what to do. Any advice?

Edit: thank you everyone for the advice. As far as that free loading comment. I was initially extremely hesitant to move in with them because I happen to be very independent. But they insisted, it was never our idea. We help them around the house. Doing errands and cleaning. So to suggest we are free loading is extremely rude.