Family invites you over

Have you  turned down invites to eat dinner from family or friends bc the idea of having to feed, burp, and change a 4-6 week old is exhausting already? My mother thought it would be a nice idea to invite me last minute for dinner at her home at 6:45pm... My 5 year old has school tomorrow and her bedtime is at 7 and my 5 week old is the fussiest at night. I'm not crazy right? Lol