The Black Widow with Spider-Man's power she has as much knowledge and experience with her powers as Spider-Man does and she still has her skills and weapons. How dangerous woud she be? And who would you like to see her fight?
I see this as a downgrade. Slightly more skilled (Pete has kung-fu now) and a few more weapons, but not nearly as smart. If anything, a side-grade in terms of power, and a definite downgrade in banter and brainy stuff.
Like, imagine the recent End of the World arc without Peter's tech upgrades that he made at Horizon, and his clever solutions to stuff. There's no way she pulls it off.
I'd like to see her fight Peter Parker at that point. Watch him deconstruct his own power set.