I would actually suggest that you offer your daughter the opportunity to try home ed in Y6 if she wants. Here's why.
Usually, trying home education for a few terms or a year runs the risk that if you don't like it, you may not be able to get them back into the same school because it might be full. Or in the case of Y7, your preferred/nearest secondary might be full and you would have missed out on the chance of a place there. That risk is gone if you home ed for Y6; if she doesn't want to continue with home ed then she could just go to secondary as usual.
Your daughter may well want to experience high school, possibly even if she doesn't expect to like it. Kids are curious, and everyone "bigs up" how exciting secondary is, so she may feel left out if she doesn't start. If she does want to check high school out, it's less daunting to be the new kid alongside all the other new kids, i.e. try it in Y7 instead of later. And then if she's not loving it, she will face the question of whether to leave. That may feel like a huge decision if she doesn't actually know what home education is like. Nobody does know what home ed is like until they try it! But if she's already had a year of home ed, she can make an informed choice to stay at school or leave. It won't be such a scary decision. Fear of the unknown often keeps kids at school longer than is good for them; some kids can be having a truly horrific time at school and still be afraid to leave.
Some (not all) primaries do endless SATs drill in Y6, with little real learning and lots of stress for the kids. Every year we see a few families join our home ed groups who are home educating for just that one year because their child was hating being hothoused for SATs.
Y5 and Y6 are often the start of very painful friendship issues at school, especially for girls. Such problems do exist outside of school, but are far less troublesome. There are aspects of the school environment which make friend issues more prevalent there than elsewhere. So your daughter's currently happy social life at school may be turned upside down later on. It may not, but be alert to that possibility.
Anyway, it's great that you are looking into this now, and then if your daughter would benefit from home education earlier than Y7, you might start earlier.