Ah yes, of course, listing your summer job on a resume would be Weird.
It would be weird to do so 40 years after the fact. How is it relevant to anything she would be applying for now?
I didn't have summer jobs but I don't put school qualifications on my CV as they're not relevant.
Telling a crowd of people about it at a political rally is not Weird.
Correct. It isn't weird when a candidate is trying to connect with "working people"
She hasn't provided any evidence that she did work there - I'm not sure how she would be able to do that now, who keeps records of stuff like that from 40 years ago just in case they ever have to produce them in the context of a public scrutiny that couldn't possibly have been anticipated. McDonalds have said they wouldn't necessarily have records from that long ago either.
She has made a claim without evidencing it, Trump has said it isn't true also without providing evidence. To be fair, proving a negative is difficult but I guess if there were people who knew her back then they might be able to confirm or deny the claim. But it isn't a fantastical claim. Very few people have been to the moon (it's 12 by the way, not 0 - I mean who have actually landed). Lots of kids going through college have summer jobs and McDonalds is quite a common one for that demographic.
But...honestly, who cares? Does this inform anyone's decision about who to vote for? I mean, I guess if she is lying it speaks to her credibility but given how frequently Trump lies that isn't something to differentiate the candidates. Talk about a nothing burger, pun intended.