She has started doing around 400 mool mantar daily and told me today that when she does mool mantar,she can feel God sitting nearby her.
I find it an interesting spiritual experience from someone who has not heard any katha on mool mantar.
I think there are quite a few variations of how much bani Sikh's read at bedtime. The very basic consists of the 5 shabads that you will find in SGPC gutkay. Taksali gutkay have then added the rakheya de shabad which have variations as well. The older gutkay sahib have 4 rakheya de shabad and the Sundar Gutka app by Taksal has 5 or 6.
Nanaksar have a variation as well and the longest variation I've seen is the Budha daal gutka sahib which has a mini Japji Sahib and Jaap Sahib added to the end.
Take your pick.
A side note, one of Dasam Guru Sahib Jee's 52 hukam is to read the salok Pavan Guru Pani Pita with keertan sohila.
I had no idea of this until recently (thanks for the SA brothers for the heads up), but here is the spiritual lineage of Sant Isher Singh Ji. Going all the way back to Bhai Daya Singh, the first panj piara. You might have heard of some of those included i.e. Bhai Maharaj Singh Ji and Bir Singh Ji who were active participants against the english colonisation of Panjab around the Sikh-anglo wars: