I hear you about being old etc. I was 46 when I got pg and am now 48 with a 10 month old.
Sure I saw young moms at the mother's group and at playgroup but I saw older moms too. My best friend is 38 and she is always saying she feels old. Well I'm 48 and if I wasn't sleep deprived I wouldn't feel old (weary) at all.
Don't compare yourself to younger moms as they are younger... and probably haven't the financial or emotional security you have.
Doesn't matter if you are over 50 or whatever when they graduate. Your child won't care as you are their mom.
If I start to feel old (weary) then I take more vitamin pills or rest more. I know the younger set at the mother's group do this too. Oh BTW mother's groups have a limited lifespan so don't worry about being surrounded by them for ages when they have outlived their usefulness then flick it off.
Sure others have had children while they were young but you haven't and thats that. You can't change it so don't think about it. It will be ok trust me, best, THK