Praise be to Allah.
It is permissible for a woman to see her husband after he dies, and for her to wash him, according to the correct scholarly opinion, which says that either spouse may wash the other after death, even if there is someone else who could wash them, because ‘Aa’ishah said: “If we could go back and change anything, no one would have washed the Messenger of Allaah (peace and blessings of Allaah be upon him) but his wives.” (Narrated by Abu Dawood). And because Abu Bakr al-Siddeeq (may Allaah be pleased with him) left instructions in his will that he should be washed by his wife Asmaa’ bint Umays, and she did that. And because Abu Moosa was washed by his wife Umm ‘Abd-Allaah. It is also permissible for a man to wash his wife when she dies, according to the correct scholarly view, because it was narrated by Ibn al-Mundhir that ‘Ali ibn Abi Taalib (may Allaah be pleased with him) washed Faatimah (may Allaah be pleased with her) after she died. That was well known among the Sahaabah (may Allaah be pleased with them) and no one denounced him for that, thus there was consensus on this point.