I don’t know her, I’ll ask and risk her unintentionally feeling bad about herself!

But seriously, that’s your choice. I would just want to know in your shoes. Hell, you used it and appreciated it, start with that! “Hey mom, I heard that parents these days consider kids out of sight/out of mind and basically cut-off when they leave the house, even for college! I know you kept me fed when I wasn’t living at home… Thanks for that!”