Yes, she'll miss out.
If you're in the UK, as a nursery worker I'm sure you're aware that reception is part of the Early Years curriculum. At my DC's school, reception was absolutely lovely, a great bridge between pre-school and more formal school when they're older.
They did loads of learning through play, and were gently introduced to the way the school runs.
They were all new and in the same boat and made friends together.
Year 1 was a big step up. The learning became less play-based, more what you'd expect at school. The kids all knew how the school was run and had all made friends.
Any child coming into school for the first time in year 1 would have been at a disadvantage to the other kids.
Enrol your DD in reception, you'll be doing her a diservice not to.
Have you hear of flexischooling? Maybe that would work for you and DD? Flexischooling is part home schooling, part mainstream school. Whether you can do this depends on the school. Some support it, many don't. But if they're under 5, I'm not sure there's much they can do as the DC aren't legally required there? You'd need to look this up if you're considering it asw this is the sum total of my knowledge about it!
Maybe join some flexischooling groups on Facebook, they're not hard to find and the parents there will be able to advise about this.
Or, just enrol her in school and know that if you feel she needs a break, you can simply take her out for a day or so when she's under 5.