First off, my condolences on your loss. I'm scared of losing my dad soon myself. Secondly, I think you may both be in the right, though there isn't a lot of information about your girlfriend here. You're not being sensitive, it was a stressful day and it doesn't help the person that was supposed to be there to support you wasn't there to do so.

However, I'm curious to know how many people in your family know of her? How she does in social settings where she is with unfamiliar people? Did she know your dad? Was she close?

If she's not comfortable around unfamiliar people or don't know your family too well, it could be a very uncomfortable, awkward and possibly terrifying situation for her to step into. Here is a bunch of people grieving and you bring a stranger in, who doesn't know these people very well. Not only that, if she's not good at the small talk or relating to people, it could be really terrifying for her to try and connect with a bunch of people grieving. Yes, she has empathy for them, but she might be feeling like an outsider to this and she's lashing out because you put her in a very uncomfortable situation.

Have you sat down with her and talked to her about why? Like I understand where she is coming from with this. The biggest piece you gave is that she didn't feel like she was your partner. Yes, I understand you're grieving. And no you're not being sensitive or selfish, but on the other hand, your partner is seeing you going through one of the roughest times in your life, and she wants to be apart of your family, but I'm curious to know what you have done to make her apart of your family? What were the conversations leading up to that point? You had a lot on your plate, did she ask to help? Did she want to be there?

I think there is another dynamic here I want to explore.