mortgage joint property after mutual divorce without claim

My son and his ex-wife taken the divorce with mutual consent without any claim. My son has purchased a flat in apartment with his wife name also on bank loan where EMI is deducted from my son's salary only from the beginning. She stated and it is mentioned in divorce decree that she has got "Stri-Dhan and others" & she has no claim in property further. She has done an affidavit also separately about the loaned flat that EMI is paid by her husband and he will be pay the loan EMI and she will not claim her share. If required she will do power of attorney etc. when it is required. Now what to do