How would you react?

So I’m watching my kids at the playground minding my business.. when this mom approaches me saying “I’m sorry but when is your due date?”.. Now I know her face her kid is at the playground usually but idk her name or anything. So I told her my due date just bc I got caught off guard…then she proceeds to saying “ omg you are so big!..”… I’m just standing there even more awkward…then she goes, I hope I didn’t offend you.. I said oh nw I’m unoffendable🤓.. she then walked away! The end!! I started laughing to myself still puzzled on what the point of it all was??? ..