Hi, and welcome! It can be so hard not to compare our little ones with other people's children. Especially with our first children, it's difficult to know what's "normal" and what "behind" is. I have extensive experience working with preschoolers and what you're describing for your dd sounds completely normal - wonderful!
My dd is 6 and is now reading at a at a solid second grade level, but didn't learn her letters, or how to write her name until she was 5. My ds knew the alphabet at 18 months, loved listening to chapter books with no pictures at 4, and could write his name at 4. He learned to read when he was 8. Both of them are very bright, curious, creative kids who are developing at their own rates.
I'll tell ya, when my ds was 5, he had a friend, also 5, who could read everything: the newspaper, adult magazines, books, etc. completely fluently. I felt kinda envious at the time. Then I realized that my husband was a "late" reader, and I was an "early" reader, and guess what? We both read well now - reading early or late didn't make any difference at all in the long run!
Hindsight is 20/20