I think saying you are proud and wanting to tell people is fine, and so you should be. Don't label it as boasting though, it is just pride, boasting is a negative word. Well done to your dd, sounds as though she has a good grasp of phonics
I was just coming to have a boast to so well done to your DD, but without stealing your thunder I will turn this into a boasting thread. My DD is year 4 identified as exceptionally gifted in science and Maths, but is a coaster. We get effort cards ever half of term which has just pinged into my inbox. At last the converted 1 ( consistently excellent effort) in Maths well done DD just because you find it easy doesn't mean you shouldn't try your best. To go with 1s in humanities, mandarin, Italian, dance, PE and IT has made me a very proud Mummy. You are considerably closer to that lovely shiny new scooter.