Awful old lady at the supermarket

I wish this wasn’t still on my mind but this morning I was food shopping with my 1.5 year old, I’m pregnant in my third trimester and we’re in a 90 degree heat wave, so I’m really just on survival mode for now. The most miserable old couple was behind me at the supermarket, they were breathing down my neck waiting for me to pay and leave while I loaded all my bags up and put them into my cart, dug around for my phone in my purse so I could get the digital coupons and my credit card, while my son was grabbing the stuff off the shelf that’s inconveniently surrounding the aisle and all in arms reach, coins fell out of my bag and I was picking them up, and I’m doing all of this as fast as I can. Then after I pay I’m putting the recipt back in my bag, and the lady behind me goes excuse me miss what kind of melon do you have in your cart (it was next to my son in the kids seat)? And like an idiot I fumbled around for the sticker and took it out and was reading the label for her and she just went ‘hmph’ and looked at the cashier and I’m pretty sure she was just trying to make sure I paid for it and wasn’t trying to sneak it out with my son (I paid for it with everything else). I don’t get why people have to be so miserable?? When I’m old I plan on being nice especially to young women with little kids. If they aren’t going to be nice, just be quiet, is my outlook.