Is it okay for a young unmarried women to share her baby or toddler photos publicly on facebook? I know at that age it is not obligated to wear niqab/hijab but since I am a adult now would it be right to show the younger pics of myself? especially when my face now very closely resembles that of my old pictures?
A young girl is either of an age and shape that is usually desirable to men, because she is close to the age of puberty, or she may be small and of an age where she is not desirable.
In the first case, when she is of an age and shape that is desirable,
The scholars have issued fatwas stating that it is not permissible to look at such a girl, because that may be a cause of fitnah and provocation of desire.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
If a girl has reached an age where she may be an object of infatuation or desire for men, then she should observe hijab so as to ward off fitnah and evil. This varies from one girl to another. Some of them grow quickly and look mature, and others are the opposite.
End quote from Majmoo‘ As’ilah tuhimm al-Usrah al-Muslimah
Based on that, if in those pictures you are of this age and shape, then you are not allowed to publish them, because publishing them helps others to look at something that is haram for them, and may lead to infatuation with the person in the picture.
Allah, may He be exalted, says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression. And fear Allah. Verily, Allah is Severe in punishment”
This is what we think is most likely to be the case with your picture; they cannot resemble you as you are now unless at that time you had reached the age at which it could become desirable to look at such pictures.
In the second case, if you were at an age when girls are not desirable to men, then there is nothing wrong with looking at them, because there is no issue of desire and no risk of fitnah.
Ibn Qudaamah said in al-Mughni (9/501):
In the case of a small girl who is not of marriageable age, there is nothing wrong with looking at her. End quote.
In al-Mawsoo‘ah al-Fiqhiyyah al-Kuwaitiyyah (40/347) it says:
The fuqaha’ are unanimously agreed that it is permissible for a man to look without desire at the entire body of a small girl who has not reached the age at which girls become desirable to men, apart from her private parts. End quote.
What we advise you to do is not publish your picture on your personal page at all, either because it is most likely that it shows you at an age at which it becomes desirable to look at pictures of women and become infatuated with them,
Or because that will open the door to others to become infatuated with the picture and to look for the person in it, and make the connection between the picture and you as you are now. This involves distractions and temptations that should be prevented, especially in times such as the present, when fitnah has become very widespread, piety has become weak and there is no religious deterrent.
For more information, please see fatwa no. 174965
And Allah knows best.