Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Only males may bathe males and only females may bathe females, with the exception of your spouse and children under seven.
Answering your question, Sheikh Mustafa Umar, President of California Islamic University, states:
Only males may bathe males and only females may bathe females, with the exception of your spouse and children under seven.
Imam Abu Hanifah argued that a man cannot bathe his deceased wife since she is no longer his wife after her death, therefore he cannot look at her. Part of their reasoning is that the husband is allowed to marry his deceased wife’s sister or a fourth wife (besides her) immediately after her death. (I’la as-Sunan, 8:223-224)
Asma bint Umays said: “When Fatimah passed away, me and Ali ibn Abi Talib bathed her.” This narration has been recorded by al-Bayhaqi in his al-Ma’rifa with a sound chain of transmission. It has also been recorded in Nayl al-Awtar with a sound chain. The companions did not object to this practice of Ali.
The majority of scholars have allowed a husband to bathe his wife and this is the opinion I lean toward.
Almighty Allah knows best.
Source: AsktheScholars.com