In the question mentioned above hajj is fardh on you. If your wife does not possess money from which she can bear the expenses of hajj with you, in this case, hajj is not fardh on your wife and it is not necessary for her to take debt. However, you can take her for hajj with you by taking debt if you want to take her for hajj and it is not difficult for you to pay the debt after returning from hajj.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband