It sounds fine but she was never Taskmaster, they took his powers kinda but She wa the Red Widow in everything but name but for Fans this matters.
If your going to use Taskmaster you need to make them either comic accurate or do a great job of making them more interesting like Zemo, they did neither in her first film and even with the arc it would not be near where I would care. I'm happy the characters we got got the spotlight, I mean except ghost who had not much going on. But now many of us fans can be excited to see a real taskmaster joint he MCU like the Mandarin before him when they brought that character back it was 100 times better then what they did before.
Just my two cents but the film didn't need another character, Bob, US agent, Red Guardian, Bucky, White Widow all got screen time and really only ghost got screwed over. We also had Valentina in alot of the film...so I think this was for the best unless they wanted this as a TV show