Praise be to Allah. It is imperative to reject the fighting between the two women to the extent one can; as narrated by Muslim (49), the Prophet (peace be upon him) said: "Whoever sees something objectionable should change it with his hand, and if he is not able to then with his tongue, and if he cannot do even that then with his heart, and that is the weakest of faith." So if one sees two matters that are objectionable, he must reject them verbally, and if they do not respond, it’s permissible to intervene between them physically, even if it requires holding their arms or hands, preventing them from greater corruption. Among the rules of Sharia, it is permissible to resort to a greater harm to prevent a lesser harm. Therefore, it is permissible to treat a woman physically when necessary by touching to address her condition. It is known that trees can cause harm to body parts, and that is a corruption worse than mere sight or touch. Ibn al-Qayyim (may Allah have mercy on him) said: "What is prohibited to touch for planting is permitted for an overriding interest, as the prohibition of silk for males is because of the resemblance to cursed women, whereas the use of what is necessary is allowed." (End of citation from "Informing the Site" 2/161). Dr. Muhammad Sadiq al-Barnu in "Encyclopedia of Juristic Rules" (8/516) explained a rule: "Everything that is forbidden to look at, it is forbidden to touch similarly, with exceptions for these matters that require the physician's assistance to treat the afflicted woman by observing her, provided that there are no female doctors to do this job. Among these: It is permissible for a foreign man to touch a drowning woman to rescue her, provided that the necessity is evident." (End of citation). If the man fears for himself from the girl, or is concerned that he might fall into wrongdoing, he should suffice with rejecting her by tongue, and refrain from intervening for any possible acts that may occur along the way. And Allah knows best.