OK. Here's the deal. Ive hassled people with JK and the related books ets, contacted staff at other EU boards.
There is no OFFICIAL source that states tha Jan has a mechanical hand or not. It is not mentioned in *any* official database entries or officially published character guides. The "story" of Jan's hand was not described in any game or story. It *may* have been mentioned in the audio versions, though this is unlikely(nb. this is very hard to check as they are near impossible to find nowdays)
Wiki's mentioning of Jan's mechanical hand, whilst not incorrect, is based on observation from the games. She is wearing it in every single cutscene in JKI. Even in the medbay scene where she isnt wearing her other gear, she still has the glove.
It is therefore a reasonable assumption to conclude one of two things:
*Jan has a robotic hand OR
*Jan's own had may still be intact and she has a glove(ie. acting as a prosthesis) which keeps its function intact.
as far Im concerned, case closed
It's one of those little grey areas that EU has. Considering Jan is a game character more than a book/comic character, its not hugely surprising thats such details are missed.