If there's no other married couple, female, her family to do this then you must do this, she's is Muslima and needs the support from other Muslims. If you don't support her then who will?!
I doubt what Shakir has said in his answer is what you're thinking of, but if that's the case then you should avoid it. Very likely she's a women of qdinar has mentioned in the comment and you should be fine. She's like your grandmother...
And women of post-menstrual age who have no desire for marriage - there is no blame upon them for putting aside their outer garments [but] not displaying adornment. But to modestly refrain [from that] is better for them. And Allah is Hearing and Knowing.https://quran.com/24/60