Do I sound insensitive for being upset about this?

I witnessed a family member’s death a month ago. I just went back to work for the first time this morning. A girl comes up to me when we’re close together and tells me that it’s the death anniversary of someone in her family as well and she has a family member in the hospital. I was talking to her about it, asked if she was okay, if her son was okay, etc. Then they had me work with this newer girl and she knew basically nothing. So I had to help her while also trying to keep up on my own tasks. We also got really busy so it was a lot. The girl with the family member in the hospital comes up and starts snipping at me in front of a group of people saying “you need to do x,y,z because you’re messing stuff up”. But I can garuntee that at least 80% of it was this new girl, no hate to her, but it was bad. After, I guess there was another mistake, idk I wasn’t around to see what originally happened. But this girl again assumed it was me and stormed off, saying how she can’t stand me, basically. I was like “???? wtf???” Because the new girl is on her phone, not keeping up, not learning anything I’m teaching her so she has to ask every couple seconds. Meanwhile im TRYING.

I feel like she thinks because I also am grieving that I’ll understand her and it’s okay if she snips at me extra. Which I get to a degree. But I also don’t think it’s fair to just target me? Not to mention, she’s in her 40’s. I feel like at that age, knowing you’re at a JOB, you should be mature enough to control yourself. I’m also sensitive because my family also targeted anger at me while grieving and I thought work would be the one safe place I had.