Using fruits and vegetables to treat skin problems
Question

I work in an E-magazine in the family and women section. All my dealings are with women. I try my best to make Da’wah through my work.
There are some health issues women ask about. Like face spots and such skin problems. Is it permissible to advise them to use some natural vegetables and fruits for this purpose? Knowing that I advise them to beautify themselves only at their homes. And that they should not show their beauty but to their husbands and mahrams. Is my work permissible?.
Praise be to Allah.If the matter is as you describe, and you (as a woman) deal with women and discuss matters that are beneficial for them, there is nothing wrong with that, rather it is hoped that you will be rewarded for calling people to Allah and spreading good among people. 
There is nothing wrong with using fruits and vegetables to treat some skin problems, so long as that does not involve extravagance. 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked: Some of my friends use eggs, honey and milk to treat freckles that appear on the face. Is it permissible for them to do that? 
He replied: It is well known that these things are foods that Allah has created to nourish the body. If a person needs to use them for something else, such as a remedy, there is nothing wrong with that, because Allah says (interpretation of the meaning): 
“He it is Who created for you all that is on earth” [al-Baqarah 2:29]. 
The word “for you” includes all kinds of beneficial uses, as there is nothing to indicate that it is haraam. 
With regard to using them for beautification purposes, there are other materials that may be used for beautification, and it is better to use those. 
It should be noted that there is nothing wrong with beautifying oneself, rather Allah is beautiful and loves beauty, but being extravagant to such an extent that it becomes a person’s main concern and he neglects many of his other religious and worldly interests for its sake, is something that is not appropriate because it is a kind of extravagance, and Allah does not like extravagance. End quote from Fatawa al-Mar’ah, compiled by Muhammad al-Musnid, p. 238. 
The fact that these prescriptions may be used by those who make a wanton display of their beauty (tabarraj) does not matter so long as your intention is to teach that to those who will use them in permissible ways. 
You should always remember that a woman should only show her adornment in her house before her husband and mahrams. 
May Allah help us and you to do that which He loves and which pleases Him. 
And Allah knows best.