Should we forbid you to drive your car if you can't fix your engine?

you should teach her and help her out... I really hate developers who are out here trying to get others fire.. dude just help each other out no one is smarter than everyone some people just do not have all the experience you might have. But we all capable of achieving the same things its just about putting the time and effort.

No is the best answer, some malware are hard to delete and also if you have not deal with one in a very long time, specially for mac users. If she is a Mac user and she had never the problem well probably is something you think is common for a Windows user. You could share your knowledge with her on how to remove malware, don't forget that you're supposed to be a team so you should help her out. Sharing knowledge is the best way to confirm yours and to learn even more.

I don't know what competence has to do with sexism. Wouldn't you ask your boss if she was a male?

Why would you? I mean, I don't know every background information, what the developer is doing, what kind of malware it is, and such things.

But for example, i am a Web or Full Stack Developer, how should i know how to remove some kind of bad program? Where should i take the knowledge from, when even google can't help me with my problem?

Only because I can bring a led to glow doesn't mean i am able to fix the lights of a football stadium.

The answer is no. She is doing what she has been hired for. I don't think uninstalling malware was a part of job description.