If  a lady is unable to rub her feet with her hands because of surgery or any other reasons that prevents her from even bending down, in that case if the water is poured from above and it runs over the entire feet and between the fingers of the feet then her wudhu will be complete because rubbing and moving your hands and fingers on your feet is Sunnah but it is not compulsory.

However, it is compulsory that water should reach that part of the limbs which are supposed to be washed. Thus, the most important thing is the reaching of water. If the water can reach the entire feet then as per shariah there is no problem and the wudhu will be complete.

And if there is someone from his relative who can assist her and wash her limbs with their hands, even then such a wudhu is considered to be performed well and there is no objection in the shariah.

This question is about wudhu, now there is another question along with it as well.

If she has undergone surgery and missed out her prayers, what is the ruling about the missed prayers? Should she offer Qadha salah or there is no need to offer or if at all or should they be offered along with Sunnah or can be offered without sunnah?

We should know that if a person is unable to offer prayer due to her surgery,  then it could be because she might be unconscious and therefore unable to offer her prayers so when she regains her conscious she will offer her full prayers. It is better that she offers even the Sunnah along with the Fardh

This is because when the Prophet (blessings and peace of Allah be upon him) missed his Fardh prayers, he offered them along with the Sunnah. Yet if it is difficult to offer prayers after being operated then she may offer only Fardh, In sha Allah there will be no sin upon her.

It is important to note that if the surgery has not made you unconscious, then do not delay your prayers.  Try to offer your prayers in whichever condition you are in. Take someone’s assistance to perform your wudhu and if it is not possible then perform Tayammum. Once your wudhu is performed and if you are able to offer Ruku and Sujood, then offer them, but if you cannot, then you are even allowed to offer your prayers while you are resting on the bed. In this situation, the feet will be towards the Qiblah so that the face too can be towards it while one will pray.

The Prophet (blessings and peace of Allah be upon him) has permitted that if one of you cannot offer his prayer while standing then he should pray while sitting, if you are unable to offer even while sitting then offer your prayers while lying on the bed and if  you are not able to offer that, then pray with gestures only but do not miss your prayers nor delay them.