What is the ruling of Islamic law regarding a mother's vow to fast, to give away her jewelry in charity, and to abandon gold ornamentation if she recovers from her severe illness?

Whoever vows obedience to Allah must fulfill it, for the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him." A vow contingent on a condition is not obligatory to fulfill unless the condition is met.

Regarding your vow: 1. Fasting: This is an act of obedience that must be fulfilled. If you specified certain days, then fast them. If you did not specify, then fasting one day is sufficient for you. 2. Charity with jewelry: This is an act of obedience that must be fulfilled. If the jewelry constitutes all of your wealth, then you must give one-third of it as charity. If you have other wealth besides it, then you must give all of it as charity. 3. Giving up adornment with gold: This is not an act of obedience; rather, it is permissible. You have the choice between fulfilling the vow by refraining from it or adorning yourself with it, in which case you owe an expiation for breaking an oath.