Yes it is possible to send a child a year later - I think it depends on the local authorities too. https://www.gov.uk/government/publications/summer-born-children-school-admission
I looked into this as my daughter is born on the 25th. You can defer by a year, but check with schools as it maybe that when they do start school they will go straight into year 1, so not really in a much better situation, also I've heard not sure how true that when starting high school they could miss year 7 and join the kids same age
Yeah it's totally fine and expected with that sort of birthday. Just send her when she's 5. Make sure your chosen school will allow her to start in reception though!
I have been wondering the same thing but sending my son earlier rather than later, he will be the oldest in his class. I wondered if this was a thing too. Hope you get your answer x