Am I justified in feeling offended when mistaken for my toddler's granny?

[QuirkyOliveQuoter]

I’m sick of being mistaken for my toddlers grandma, am I justified in being (quietly) offended?

Im 37. I don’t think I look bad or particularly old! but its happened 2 times in past few days-
I picked her up from nursery and it was a worker I’ve never met before. As she didn’t know who should be doing pick up, she went and got someone else. She came and laughed and apologised and said, ‘oh sorry, I was just saying I don’t know (xxx)’s ma-‘ she literally stopped herself saying mam and looked and me for a split second, then said ‘…. relatives’ - it was so obvious she thought I was grandma that one of the other mothers I get on really well with made a quiet joke about it when she went to get my child.
I wouldn’t have minded but I heard her say to the next lass, ‘sorry, I don’t know everyone yet- you must be (xxx)’s mammy’ !
It happened once before with a health visitor, she said ‘are you mam or….?’

Then today on the bus someone said to me, ‘are you mam or granny?’

i was fuming 🤣 is this a normal question? I don’t think of myself as being a sensitive or self conscious person in the slightest but I honestly think it’s so rude. I get I’m not obviously 20- but its different if I was obviously of granny-ing age but surely if it’s ambiguous it’s rude to ask?
It’s just someone looking at you and thinking you’re far to old to be a mother makes me feel so self conscious, I struggled with infertility for so so so many years and I don’t feel I look old enough to be considered Gran over mother!

I’ve told this on MN before, but I was mistaken for my children’s grandma when I was 32! I was utterly horrified because my children’s actual grandparents were in their 60s at the time so I assumed I must look that age. But on further conversation with the woman who said it, it transpired that this was her first visit to the UK, and she was from quite a working class area of New York, where she and almost everyone she knew had started having their babies at 15/16, so whilst I was still offended, I could see how she’d had a very different cultural context to mine!

Hugs OP. Don’t overthink it.

Im obsessed with you everything I've written you've commented on. Its not impossible I don't know anyone who had their first kids in their 30s or 40s. I know people who have had their 3rd, 4th kid in their 30s but not a first.