From the bottom of my heart, thank you to each and every one of you who replied to my post and gave their opinions. I was very nervous of putting my question out there but I am so glad that I did. I can't express just how helpful it was to hear different opinions and approaches.
As lots of you suggested, I sat down with my DD this morning before school and we had a long chat about her taking on more responsibility for elements of her life etc. She surprised me with lots of her comments. For example, she said she would still choose to stick with the 'no phone till after she was ready in a morning' rule as she thought it was sensible. We discussed bed times/TV off times and she suggested that on weekdays she turns the TV off at 9.15 with the option of reading until 9.45 and then at the weekend she has suggested TV off at 9.30 with the option of reading until 10. I was obviously pleasantly surprised with her suggestions and it has helped me to see that she is a very sensible and level-headed girl.
A few people suggested that doing homework straight after school wasn't the best option as she may need down-time first. We talked about homework strategies and she said she would rather still get her homework done on the day she gets it set - she says she will just have a drink and snack and maybe a catch up with me before she starts her homework. Which, again, is very sensible.
The checking of messages/social media use is still a grey area for me. As several people have pointed out, if she thinks I am checking her phone constantly, she will simply start to delete anything she doesn't want me to see, which totally defeats the object of me trying to keep her safe. I have said that moving forwards I won't routinely go through her messages but have made it clear that she can come to me with any concerns she may have. In the past she has told me when friends at school have received inappropriate photos from boys and we have discussed what she should do if this happens to her. She is also very well aware of the dangers of strangers creating fake accounts to entice children into trusting them etc.
The 'no phones at night' rule is here to stay for a while longer and she has agreed with the logic for that. Having said that, I will bear in mind what some of you have said about how she will need to learn to self-regulate her nighttime phone use herself at some point. I will perhaps re-address this one in a year or two.
Once again, thank you to every single person who has left a message. I appreciate each and every one of them. I haven't really used MN much before now but will be doing so more often. If I can offer any advice/opinions/a listening ear to any one of you in return, please do not hesitate to ask. Thank you once again.