It might be important to note that those numbers are just the main universe (the count for the alternate versions of the characters are held individually so it would take some time to count them since the major heroes each have like 30+ alternate versions if not more) and those are only the main appearances apparently. There is also a minor appearance category for about 50 to 200 for each of them. Not sure where they made the difference for that.
If you add the minor appearances, Wasp surpasses Black Widow. Carol and Wanda are no longer tied, Carol is like 15 issues above Wanda.
I just checked the minor appearances and some of them make no sense. For examble Wasp's appearance in History of the Marvel universe 3 is listed as a minor appearance but she is in actually several pages in big panels so that makes no sense. We should count the "minor appearances".
That way the new top 10 appearances for female characters in the main universe is:
1. Storm - 1889
2. Invisible Woman - 1821
3. Captain Marvel - 1424
4. Scarlet Witch - 1408
5. Wasp - 1280
6. Jean Grey - 1269
7. Black Widow - 1261
8. She-Hulk - 1214
9. Mary Jane - 1170
10. Kitty Pryde - 1134