Joh 13:13 "You call me 'Teacher' and 'Lord,' and rightly so, for that is what I am.
Joh 13:14 Now that I, your Lord and Teacher, have washed your feet, you also should wash one another's feet.
Joh 13:15 I have set you an example that you should do as I have done for you.
have washed your feet, ye also ought to wash one another's feet: by which he does not mean barely, that they should perform this single action; but as this was an instance of humility and condescension, and doing a good office to strangers and travellers, and was afterwards an expression of love to the saints, see 1Ti_5:10, so he would teach them hereby, to behave in a spirit of humility and condescension to one another, to do every kind and good office, and by love to serve one another in all things.
1Ti 5:9 No widow may be put on the list of widows unless she is over sixty, has been faithful to her husband,
1Ti 5:10 and is well known for her good deeds, such as bringing up children, showing hospitality, washing the feet of the saints, helping those in trouble and devoting herself to all kinds of good deeds.
If she have washed the saints' feet; which was usual in those hot countries, where they wore sandals only, partly for refreshment, and partly for the removal of dust and filth, contracted in walking; instances of this we have in several places of Scripture, Gen_18:4. It was such a common piece of civility, that our Lord complains of the neglect of it towards him, Luk_7:44. It was what he did to his own disciples, and in so doing set them an example of what they should do to one another, Joh_13:14 and being a mean and low office, and which very likely was done by the servants of the house; the sense may be, if she has condescended to do the meanest office for the saints.
I think this spells it out pretty well.