Maybe.
But when attorneys advertise wrongful death actions as a way to "seek justice for a loved one," before it's all over the undertaking can become a self-inflicted wound for the family bringing the action. So one has to question whether such as action makes sense against a dead defendant especially when the amount of money that could be gained is so very small.
To bring suit, GP's family would have to pay an attorney. I could be wrong, but with such a small estate, I'd be very surprised if an attorney would work on contingency. Plus it would seem there could be witnesses needed from close to the west coast of the US all the way back to the east coast/FL. So there would be travel costs that have to be paid by GP's family. (Not counting their own travel.
Maybe some of that could come from the Foundation but I doubt the other expenses could.)
Further, it seems to me (could be wrong!) any wrongful death lawsuit would be brought in FL. Florida law does not allow "relatives" to file wrongful death suits. (And BTW, neither does NY.) So technically any suit must be filed by the executor/personal representative for the victim's estate. I don't know who that is for GP. It could be both parents but it might not be. And if both parents aren't personal reps for GP's estate, they don't have equal rights to decide whether to file.
Wrongful Death Lawsuits in Florida
Wrongful Death Lawsuits in New York
And even if the personal rep filed & won on behalf of the estate, I am confident the full amount of BL's estate would not be awarded. Normally costs of "administration" (all legal fees including a fee for the personal representative/executor), some funeral costs (not totally relevant here but eventually something legal will have to be done with the remains that were found), any federal income tax owed, most debts that existed at the time of death, and so on would be paid before any court judgment GP's estate might receive would be paid (assuming they won, of course. We don't really know what LE knows that could be brought in.) I'm not an attorney but it's even possible some of the funds in BL''s estate could be used for legal representation/witness travel to defend against a wrongful death lawsuit brought against his estate (meaning BL's estate could be insolvent long before the end of the trial. Not even crumbs left to collect.)
Most important IMO, during a trial things likely will be said about GP that the family might prefer to keep private. I'm not suggesting those things would be intentionally used as a defense but unlike WS, a courtroom is not designed to be especially "victim friendly." That's not its purpose. So for example, the "dine and dash" story by the MP manager might get repeated and might be repeated about other venues. Mental health & drug use wouldn't be off limits. Even the Moab stop sworn testimony (including testimony from the female park ranger) might paint GP in ways her family would rather not hear and would rather others not hear either. And last, it might turn out BL was not "leaching off" GP as much as has been claimed here especially if GP lived rent-free with various members of BL's family & rent-free in the L's condo. (Protecting the memory of the family member is often more important to surviving family than "receiving justice" through financial compensation. At least in my experience.)
Right now, the GP Foundation store is selling merchandise (stickers, notebooks, cups, t-shirts, mouse pads, etc.) with GP pictured as an angel. A lawsuit could endanger that characterization by making her human faults prominent. And for what? Pennies from a dead defendant?
JMO