She does not have any wealth apart from jewellery – should she sell some of it in order to pay the zakaah on it?

No File Exists
Check below answers in case you are looking for other related questions:
It is permissible for a wife to give the zakaah of her wealth to her husband
Is there any zakaah on their house, shops and jewellery?

No File Exists
Related Answers:
He helped his father in his business; is there any sin on him because of his father’s haraam dealings?
Paying zakaah on a fund collected by a group of employees
No zakaah is due on rental cars and delivery trucks
It is permissible for a wife to give the zakaah of her wealth to her husband
Is there any zakaah on their house, shops and jewellery?

Recommended answers for you:
Ruling on a Muslim entering a church
Which is better – breaking one's fast when travelling or fasting?
Praying in a moving vehicle
Bid'ah Hasanah ("Good Innovations")
Will the prayers of one who drinks alcohol not be accepted for forty days?