A woman’s jealousy towards her co-wives is something that is entirely natural, and it is not something that only some woman feel and not others. Hence she will not be called to account for it unless she transgresses the limits and lets it lead to wronging her sister, which is something that Allaah has forbidden, by backbiting or spreading gossip or demanding the divorce of her co-wife or plotting against her and so on. 

Al-Haafiz ibn Hajar (may Allaah have mercy on him) said: 

Basically, jealousy is natural and is not something that only some women feel and not others, but if a woman oversteps the mark then she is to be blamed. The guideline concerning that is the hadeeth (narration) which was narrated from Jaabir ibn ‘Ateek al-Ansaari, who attributed it to the Prophet (peace and blessings of Allaah be upon him): “There is a kind of jealousy which Allaah loves, and a kind which Allaah hates. As for the kind of jealousy which Allaah loves, it is jealousy when there are grounds for suspicion. And as for the kind of jealousy which Allaah hates, it is jealousy when there are no grounds for suspicion.” 

Classed as hasan (sound) by Shaykh al-Albaani in al-Irwa’, 7/80. 

So jealousy on the part of the husband and wife, if it is of the type that is part of human nature which no woman is free from, then it is excused, so long as she does not overstep the mark and do or say anything that Allaah has forbidden. This is the way in which the reports from the salaf (pious predecessors)which speak of women’s jealousy are to be understood. 

Fath al-Baari, 9/326. 

Ibn Muflih (may Allaah have mercy on him) said: 

Al-Tabari and other scholars said: Jealousy on the part of women is to be overlooked and they are not to be punished for it because it is part of their nature. 

Al-Adaab al-Shar’iyyah, 1/248 

Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said, commenting on the hadeeth which describes ‘Aa’ishah breaking the vessel of one of her co-wives: 

They – i.e., all those who commented on this hadeeth – said: this indicates that the jealous women is not to be taken to task for what she does, because in that case her reasoning is overshadowed by the strong anger that was provoked by jealousy. Abu Ya’la narrated from ‘Aa’ishah with an isnaad (chain) with which there is nothing wrong a marfoo’ (directly attributed to the Prophet)report which says: “A jealous woman cannot tell the bottom of the valley from its top.” Fath al-Baari, 9/325 

The jealousy that occurred on the part of the best of women is something which no one can avoid, and they will not be taken to ask for it because it is not an action that transgresses the laws of Allaah.  

The jealousy that Sarah felt towards Hajar comes under this heading. For a woman to ask her husband not to let her see her co-wife and not to make her live with her is something that cannot be denounced. It should be noted that the scholars said that Ibraaheem (peace be upon him) is the one who took Hajar and her son away, and Sarah did not ask for that. 

Al-Haafiz ibn Hajar (may Allaah have mercy on him) said:  

And it is said that Sarah was intensely jealous, so Ibraaheem took Ismaa’eel and his mother to Makkah because of that. 

Fath al-Baari, 6/401 

This is also indicated by the words of Hajar: “O Ibraaheem, will you go and leave us in this valley in which there are no people and nothing?” She said that to him several times, and he did not answer her. Then she said to him: “Is it Allaah Who has commanded you to do this?” He said: “Yes.” She said: “Then He will not forsake us.” Narrated by al-Bukhaari, 3184. 

It was narrated that Ibn ‘Abbaas (may Allaah be pleased with him) said: When what happened between Ibraaheem and his wife happened, he went out with Hajar and Ismaa’eel, carrying a skin full of water…. Narrated by al-Bukhaari, 3185. 

Al-Haafiz said: 

The words of Ibn ‘Abbaas – “When what happened between Ibraaheem and his wife happened” -  “his wife” refers to Sarah and “what happened” refers to Sarah’s jealousy when Haajar bore Ismaa’eel.

Fath al-Baari, 6/407 

And Allaah knows best.