Bridesmaids selection

You don't have to ask someone else to be your bridesmaid just because they asked you any more than you have to invite to your wedding everyone who has ever invited you to theirs! It's inevitable that there will be some mismatch as different people have different sized friendship groups and families (e.g. if you have six sisters and want them all as bridesmaids, you're not going to have much room left for non-relatives, whereas someone who has no siblings at all won't have that issues!)

If you're worried that your friend may assume she is going to be your bridesmaid, it might be worth mentioning that you are not having any/only having family etc at an early stage. But most people realise that just because they ask you, it doesn't mean you will ask them.

Only say yes if you do want to be hers. I do think people expect it back personally so maybe also say now. But also, you don’t have to explain. I didn’t ask my friend who I was bridesmaid for and she ended up not coming to our wedding. She said it was childcare but I knew it wasn’t the reason, but also no hard feelings as I am not like that as a person. And my husband is best man for someone next year who wasn’t ours a few weeks ago. If people are adult enough they won’t care.