why is one easier to buy for than the other?

[SouthernOne]

I have two daughters, eldest 24 youngest almost 22.

Eldest is so easy to buy for but the youngest leaves me struggling every year. Made even worse that is it her birthday just after christmas

Just venting really:)

What happens when you ask her what she'd like?
I know people whose families fret they are hard to buy for, but often the person says what they would like but buyer thinks some items aren't "proper" presents, so recipient is made to feel ungrateful for stuff they said they didn't want.

She has told me what she'd like :) Trouble is her sister likes things that cost a lot and I like to spend a similar amount on each of them. I know, that says more about me that her!

I have the same though my DCs are younger. Every year one or other of them are really hard to buy for. It drives me nuts as I spend roughly the same on each of them. The one year I found it pretty easy to buy for all of them, ds's pile was huge compared to the dd's ones even though I'd spent the same on them. I can't win!

No, it's nice that you want to spend the same.

My mother tells me I am difficult to buy for. I never like to ask for anything expensive, which doesn't help.

I know it's dull but vouchers you know she'll use might be a good option. So rather than M&S "because everyone shops in M&S", something where you know she personally spends her money - Nandos, local cinema or pub, clothes shop that she definitely goes to (check they can be used online), book tokens.