1) if your aunt had given promissory note you should have filed summary suit to recover the loan amount of Rs 25 lakhs .
2) court would have passed order to direct your aunt to deposit money in court or given you decree if defenses sought to be raised were moonshine or sham defenses
3) since you have already file suit for attachment before judgement and court has granted attachment your aunt will not be able to sell the property unless amount payable to you in the suit is repaid
4) it is necessary to peruse suit papers and orders passed by court to advice .
5) your mother should also have filed summary suit against your aunt to recover the loan amount . since your mother has no got any attachment order by court her interests are not protected