Ordering bridesmaids dresses?

So my wedding is October 1st, 2021 (6 months away!) And I asked my bridesmaids to have their dresses ordered by the end of March. No one has ordered their dresses...the day I asked them to be bridesmaids (July last year) I told them my expectation was for them to be ordered by the end of March. I'm giving them the option to pick any dress as long as it's in the same color so they can chose what they want and an amount that's a bit more feasible for them.. they are now telling me that there's plenty of time and they want to wait, I'm rushing them. I'm genuinely upset and trying not to go bridezilla lol. Am I rushing them, cuz I feel like they need time to order their dress, make sure they like it and that it fits, get alterations if they chose, or return and order a new one if need be.