As someone with experience of the Middle East (you're not specific as to which country, but none of them are a picnic) I'd say that you need to have a conversation with her.
You need to tell her that despite where anyone comes from, what matters is that you love her and you don't judge her, and she is still your daughter and always will be, and she has your full and unconditional love and support.
Second, you need to say that although the UK and yourself have no problem with her being a lesbian, the ME is not so tolerant and forgiving. If/when she goes back there, she needs to be extremely careful about what she says to ANYONE and that includes her friends and family. You'll know better than we do that a simple slip-up can result in serious consequences e.g. Prison.
You need to tell her that the ME is not going to change. It's not fair, and it's not nice, and it's not what either of you want, but she will never be able to live a full and complete life there. She will always be hiding herself when she is within those borders, at risk of being found out through a slip of the tongue. She needs to really absorb this and understand that her future must be in the UK or another tolerant country, which means Europe, or other Anglophone countries like the USA or Australia.
With that in mind, she needs to focus on her life here and her friends here, because she will not be able to maintain her relationships in your ME home unless her friends come to visit her. She may even discover that she doesn't want to maintain relationships with people who cannot accept that she is a lesbian.
You're not alone, there are plenty of parents out there with non-heterosexual children. I'm sure you will find some to talk to.