Robert Titzer (Your Baby Can Read creator) has said that babies learn to read because they intuit phonics rules. There is a phonics rule that an e at the end of a word makes the vowel say its name. In rat, the a says ah. But in rate it actually says a. Well my younger daughter always pronounces “have” to rhyme with “cave.” I’ve noticed this since she turned 3. She’s almost 4 and I haven’t corrected her yet to avoid confusion. Obviously she intuited this rule. No one ever explained it to her. Have happens to be an exception to this particular rule. Have you seen this kind of thing with your kids?
Yes on many occasions in many children learning to read. I would suggest you correct her though. It’s easy enough to explain that that word says have and is slightly different to most times when their is an e on the end. She will be fine with it, not confused. However if she continues to read it incorrectly she may find it hard to fix later and will not learn the valuable idea that the English language isn’t perfectly logical.
It is a very good sign that she is picking up on these rules, it will allow her to progress independent of your continued imput. She is teaching herself 
very cool.