Device ownership, apple ID, and why won't my password work?

If you transferred the iPad without performing a reset, the old and new contents will be intermixed and the appropriate Apple ID used for each, or delete whatever piece is owned by the other ID and re-download it under the now-preferred ID.

Here is: How to factory reset your iPhone, iPad, or iPod touch - Apple Support which transitions all contents and transitions Activation Lock.

It seems like that the iPad is stil paired to your wife's Apple ID

If the iPad is not listed under devices, it is not paired to your Apple ID I am afraid