My friend has a problem

I was talking with (to) my friend, and she (has) a problem with her job.
She likes her job but she doesn't like the person who works with her. (she does not like the person she works with/is working with)
The person works (in this job/at this company) more longer than she (does).
So she can't tell him "Please do your work carefully."
The person stresses her out.
When I listened to this stuff, I wanted to encourage (comfort) her but I couldn't.

Between (), means it's not really an error, but how you would write it more naturally, in a better style.

My friend has a problem

I was talking to my friend, and she has a problem at work.
She likes her job but she doesn't like someone she works with.
The person has worked this job longer than she, so she can't tell him,

"Please do your work carefully."
The person stresses her out.
When I heard this stuff, I wanted to encourage her but I couldn't.