Yes, I've experienced that - and not just with letters, but with numbers too - with both of my dc. It helped my dc to have an alphabet chart and number chart in front of them. I just put it in a special school folder for them. I also traced it with my finger on the chart if they made an error, or used my finger like a pencil to pretend write it for them on their paper. They did better with the visual of the chart, and with the bodily-kinesthetic modeling with the finger. I don't think this is anything to be worried about - it's very common.
I do think you are right to have her correct it right away though. I would have her look at a model or pretend write it with her finger though, as these will be 2 ways she can commit it better to memory. One other thing that helped one of my ds's as he got older was just to look for that particular letter or number in the book or workbook he was doing before he wrote it. I still see him do that for 6's and 9's, p's and q's.
I'm so glad your dd's reading is going well now - hooray!
You are wise to keep careful tabs on what she's doing, but it sounds like she's right on track!
In Christ,
Julie
. Even when she was learning to print she didn't reverse letters often at all. This isn't usually with the copywork but in her writing at other times when she isn't copying anything. For example when writing a birthday note to a cousin. Yesterday she did reverse the letter g in her copywork but that was the only time so far during copywork. I wrote a thread last week about her regressing in her reading with simple word mistakes/substitutions but she seems not to be doing this so much now. Her reading has drastically improved recently so could it be that she is concentrating on new skills? I did gently correct her but instead of fixing the two g's that were incorrect she changed the one that was correct to match the two that were incorrect. 
. She has also been doing some mirror image writing. This hasn't happened during copywork at all though. Also, these are NOT letters that she used to reverse when she was first learning to print but totally different ones. Just wondering if anyone has had a dc do something similar and what to do to correct it. Or is it something that they eventually grow out of. Any thoughts?