Idk, from (my personal) experience with emotionally volitile situations, my guess would be that she is holding back because she hasnt processed it enough to bring it up (without being too mean or too kind and regretting it). She needs to work out how she feels about the situation.

It must have been something pretty bad for the negativity to outweigh all the good he did.

Either way, the info provided (or lack thereof) its not enough info to make assertions like that and, worst case, could make OP belittle her feelings by calling her out (and in the process force her to explain how she feels before she has fully processed it, which will absolutely not go well). Plus if OP brings up her lack of concearn for him that will come across as extremely narcissistic.

People need to be allowed to process traumatic situations and more often than not that means biting their tongue and not talking about the situation at all until their emotions settle down and they can think/speak rationally.

She is considering leaving OP so should get all the space she needs, instead of having her partner get it into their head that she is being selfish (its just a recipe for disaster) because of assumtions like that.

Edit: Assumptions in situations like these are almost always wrong (or at least very risky) because of incomplete data. OP needs to wait for their gf to explain how she feels, then judge from that how to proceed with said information.