I thought red too at first, I think we are seeing the sun hitting her black feathers. Look at the bottoms of her feet. If they are pinkish white, she is probably and Orp or Aussie. I can tell the difference to see them together because of the slight body shape and head shape difference, but not in this picture. If they are yellow, probably a Jersey Giant.
I really doubt she is a sex link because there is not gold in her for starters and they tend to have a different shape about their head and comb.
If you have any of these I think you will be quite happy. She is a pullet just coming into lay so she may fill out a little more for you. You have cared for her well, she looks bright eyed and vigorous and that is the most important thing.
Enjoy those eggs!