A menstrual wife can washing husband's head and combing his hair.

Hadith

Narrated Urwa : 

A person asked me, "Can a woman in menses serve me? And can a Junub woman come close to me?" 

I replied, "All this is easy for me. All of them can serve me, and there is no harm for any other person to do the same. `

Aisha told me that she used to comb the hair of Allah's Messenger (ﷺ) while she was in her menses, and he was in l'tikaf (in the mosque). He would bring while she was in her his head near her in her room and she would comb his hair, while she used to be in her menses."

Sahih al-Bukhari 296 In-book : Book 6, Hadith 3

Hadith

حَدَّثَنَا إِبْرَاهِيمُ بْنُ مُوسَى، قَالَ أَخْبَرَنَا هِشَامُ بْنُ يُوسُفَ، أَنَّ ابْنَ جُرَيْجٍ، أَخْبَرَهُمْ قَالَ أَخْبَرَنِي هِشَامٌ، عَنْ عُرْوَةَ، أَنَّهُ سُئِلَ أَتَخْدُمُنِي الْحَائِضُ أَوْ تَدْنُو مِنِّي الْمَرْأَةُ وَهْىَ جُنُبٌ فَقَالَ عُرْوَةُ كُلُّ ذَلِكَ عَلَىَّ هَيِّنٌ، وَكُلُّ ذَلِكَ تَخْدُمُنِي، وَلَيْسَ عَلَى أَحَدٍ فِي ذَلِكَ بَأْسٌ، أَخْبَرَتْنِي عَائِشَةُ أَنَّهَا كَانَتْ تُرَجِّلُ ـ تَعْنِي ـ رَأْسَ رَسُولِ اللَّهِ صلى الله عليه وسلم وَهِيَ حَائِضٌ، وَرَسُولُ اللَّهِ صلى الله عليه وسلم حِينَئِذٍ مُجَاوِرٌ فِي الْمَسْجِدِ، يُدْنِي لَهَا رَأْسَهُ وَهْىَ فِي حُجْرَتِهَا، فَتُرَجِّلُهُ وَهْىَ حَائِضٌ‏.‏