Get it taken care of now before the money ends up invested in a scam and disappears. Ask me how I know about this one.
If there's no risk of that, then just talk to her about it. Hell, even feign some (minor) financial misfortune where the money would make things a lot easier on you. Look at the records. But, is everything settled? Are the lawyers, funeral directors, accountants, and taxes all paid? That can take a year or more to settle unless the executor has a ton of time and experience with the process. Ask for an update, talk with her about it, sympathize with the enormity of the task. Either experience real empathy or fake it, hell I don't care. Whatever gets the job done.