Bridesmaid already busy on potential wedding date?

Hi everyone, this is my first post!!
We got engaged in November 2024 and are just starting to look at venues. We ideally want to be married next year, there’s a venue we love and are going to see it this week, initially looking at a November 2025 date, however they have offers for May 2025 which make a Saturday in May the same price as a Friday in November (about 5k)
Obviously I know that it will be a super busy few months to plan a wedding in just under 6 months but a Saturday in May for 5k is sooo ideal for us and we could never afford it otherwise!
My dilemma is I reached out to my bridesmaids (not officially asked yet but we’ve been friends since we were 2 so she knows she will be a bridesmaid) and one of them have said the potential date is her partners 30th birthday and they’ve booked to be abroad on that weekend. I’m really torn because I can’t imagine getting married without her, but (if I can be brave enough to try to plan a wedding in 6 months) this date would be perfect. Would I be horrible to book it anyway and potentially cause her to cancel her partners birthday trip?