The personal representative(s) of an estate have standing to sue on the estate's behalf. If there were none, and perchance they won, money would come into the estate and there would probably have to be one appointed. Chloe's estate contains choses of action, that is, rights to sue, against RCCI and IMO against SA. However, again IMO, this would not mean they could be forced to sue SA or are somehow neglectful in not pursuing it as the PRs are also the heirs-at-law and are under no obligation to pursue every case to maximize the value of the estate.
Re whether there are issues of fact, RCCI has submitted pictures and so has MW. Even though the photographs seem questionable, MW is saying to the court that whether or not something is impossible is the province of the jury and therefore plaintiffs should survive the 12(b)(6) motion. That IMO will be enough to get them by at this early stage of the proceeding.
Note that this only would get them to discovery, not to trial. Defendant would have another opportunity to ask the judge to dismiss the case after discovery is completed, called "summary judgment". I think they will have a better chance then. MW's questionable photographs won't get them by at later stages because the facts will have been better developed through discovery. Right now we are legally in a very early stage of the proceeding; defendant has not even filed an answer and grounds of defense yet.