Ex-teacher here. I wouldn't. Firstly because it's quite a public gift and one that's not easy to just put away out of sight. They have to put the flowers somewhere for the whole parents evening, there's often not space to store a bunch of flowers, and they possibly will need to wait for hours before getting them home and in water.
Lots of parents who come after you will make comments/"jokes" about it, about how they don't get presents at their job, about how it's not a bad life being a teacher, feel like they have to justify why they haven't got you anything.
Secondly, I really disliked receiving gifts specifically on parent's evening. When a parents evening meeting doesn't go well and it results in tension, a gift on the table between you just feels awkward, like its highlighting the change in mood. If you are going to get anything, get it another time e.g. at the end of year, Christmas, at the end of a half term etc.
Thirdly, I really and completely genuinely (I'm anonymous so would tell you if I'd rather have the gift) would prefer a card, especially handmade. Not just a generic "thanks" card that says "Dear Ms. Jones Love Sarah" but an actual thoughtful card with nice words in it, preferably from the child but if not possible then you. Include specifics about how the teacher has helped and things they've helped with, how much of an impact they've had etc. I stopped teaching years ago and have moved house several times but I keep those things and they still make me emotional.