Firstly, you will have to ascertain as to whether she is eligible for Zakaat or not. This is not possible without discussing the matter directly with her as she is the only one that will be in the position of disclosing her financial position. Assuming she is not eligible for Zakaat and you assisted her with Zakaat funds without investigating the matter, then your Zakaat will not be discharged. It is therefore extremely important that you investigate the matter before discharging your Zakaat.
Secondly, you should assure her that this is a confidential matter between you and her and she shouldn’t feel hurt as Allah Ta’aala has made it permissible for her to receive Zakaat funds if she qualifies as a recipient (for Zakaat.)
Now, if her liabilities exceed her Zakaatable assets (whether in the form of voluntary investments, gold and silver jewellery and coins, cash, etc.) then she qualifies as a recipient of a Zakaat, otherwise not. Her vehicle, home, household furniture (with the exception of TV sets, DVDs and other items of entertainment) are excluded from Zakaatable assets.
Once a recipient of Zakaat has been indentified there is no need to inform him/her that they are being assisted with Zakaat funds. The Zakaat funds should be physically handed over to the recipient or transferred via eft into the recipient’s bank account. The recipient may then utilize the funds to offset his/her debt or utilize the funds as desired.
Alternatively, the recipient of Zakaat may appoint a particular person as his/her Wakeel (representative) to receive Zakaat on his/her behalf and to discharge the Zakaat to a particular institute/individual on his/her behalf. In this instance the representative (of the Zakaat recipient) will receive the Zakaat and then pay the beneficiary as stipulated by the recipient. This method serves as a suitable alternative when one is unsure whether the recipient of Zakaat will use the funds in the correct avenue or not. By adopting this procedure there is certainty that the Wakeel will dispose of the Zakaat funds in a most suitable manner.
You cannot pay Zakaat directly to the creditor as it is necessary for the eligible recipient (or his/her appointed Wakeel) to take possession of the Zakaat funds for the Zakaat to be discharged.