I like what Katie-Nana was getting at: you can still honour your wife's mother by naming your daughter some diminutive or variation of the name "Therese" which is sort of a compromise.
For example:
Adoralyn Tess Wentworth
Adoralyn Theresa Wentworth
Adoralyn Reese Wentworth (I'm pretty sure 'Reese' is used as a nickname for 'Therese' but I don't know if you want to go the nickname route).
Adoralyn Terry Wentworth
You shouldn't have to name your baby anything you don't want to name her. It's all about compromise and if you really feel uncomfortable with giving your daughter the middle name Therese, you should talk to your wife about it and I'm sure you two can work something out. If you think you can live with it, seeing as her middle name won't be used in real life very often unless she choses to have it used, then go for it. Or, another alternative is giving her two middle names, (Adoralyn Paige Therese Wentworth or Adoralyn Therese Paige Wentworth) so you can have honour both your sister and her mother, but I don't know if you would want to go for that considering your little boy only has one right now.
Anyways, I really hope this helps and I wish you the best of luck! (by the way, I think all of the names you picked out for your twins are adorable!)