All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is Sunnah to make a grave deep and wide to protect the corpse from beasts of prey. There is no difference between a grave of a man or a woman. Ibn Qudaamah wrote in his book Al-Mughni: “Imam Ahmad said a grave has to be deepened equal to the height of the chest of a person and the grave of a man and a woman are same; there is no difference between them.
The Prophet said: “Dig the grave deep, make it spacious and prepare it well.” [Ibn Maajah]
It is desirable to recite the following Du'aa’ (supplication) when placing a body into the grave. The supplication is: “Bismi Allaah wa ‘ala Millati Rasooli Allaah” (In the name of Allah, and in accordance with the tradition of Allah's Messenger) [At-Timithi and Ibn Maajah]
It is desirable to cover only the graves of women by a cloth sheet as reported from ‘Ali that 'he passed by some people who had covered a grave after burial of a man. He pulled out the cloth and said, it is done only for the graves of women.’ [Al-Bayhaqi]
The most suitable person to place a corpse of a woman in her grave is her husband, then her unmarriageable relatives. If they are not available, then other female fellows should place her in the grave; if the women are not available, then the aged male person may bury her.
Allah knows best.