I think others will be able to answer this better than I can, but isn’t it because Hamas, and the other Jihadi terrorist groups that have bought hostages off Hamas (like the Bibas boys and their mother), are going to such great lengths to keep the hostages hidden away, particularly in the terror to tunnels? As in, they are for the moment so far out of reach? This hurts my heart to write, but don’t the intelligence services believe that only 50% of the 101 hostages are still alive? Possibly less. Maybe not having that information is also complicating matters.
Apparently Sinwar is, or was, surrounding himself with 15 of the ones he thought were are most valuable in an attempt to save his rotten skin in a raid situation. They must be very hard to locate, to get to surely, for that reason?
Maybe because this poor woman was not seen as “valuable” (as in, they couldn’t use her as leverage) meant the Palestinians holding her were not that bothered about keeping her presence a secret. Hence it was a relatively straightforward operation to execute.