As others have said, please try to avoid labelling her as "gifted" or any other synonym of that. It creates a huge amount of pressure for her to live up to.
Just because she is currently ahead of some other kids in her reading and maths capabilities, there is no reliable guarantee that that will continue. They all develop at different rates.
My daughter started school unable to read despite my attempts to teach her using phonics - she is moderately dyslexic so it didn't work for her. After a year or so she taught herself to read (more or less - I do exaggerate slightly) using word recognition, and now doing REALLY well in some academic disciplines - she reliably comes top of her year group in end of year English exams at her highly selective secondary school.... But, she's still not great at maths and terrible at PE, so would I say overall she is "gifted"? No more than any other child.
They all turn out to have their talents and their struggle areas, and my real point is, it's hard to predict what these will be at 4, when they are still changing and developing all the time.
If your daughter starts to feel you take pride in her accomplishments and the fact that she is ahead of others, she may then feel she lets you down if this state of affairs doesn't continue....
Nurture her interests and talents and also help her improve in the things she finds harder. And enjoy this precious time - it goes so quickly.
And I hope none of this sounds harsh. It's absolutely clear you love her and want to do the right thing for her. My personal opinion is that the right thing right now is to take your foot right off the gas pedal, and don't worry about "stretching" - she is years away from the point where it can become a concern (with kids getting bored in class by a limited curriculum and acting out). At her age, everything is new, and she won't be bored by it!