Everyone grieves differently. Some people want to talk about it, others want to be distracted from it. Only bring it up if you think she’s in a sharing mood, and let her drive the conversation.
You could say something like, “I know it must be difficult right now, but if you want to talk, I’m here for you.”
If she does want to talk, you could ask questions like “What was she like?” People like remembering good times if they can, and it can help them process the loss. But also, some people really don’t want to do that with coworkers. Be prepared for either, and don’t take it personally if she doesn’t want to share.
HSAs are a misdirect to get you to ignore how shitty high deductible plans are. Never take the high deductible plan.