Dear Yong Peng,

> Bhante, thanks for pointing that out. Can we insert a word somewhere
> to keep bhikkhunii and upaasikaa in dative?

I don't see any way that could be done. But what one could
do is to take bhikkhuniina.m and upaasikaana.m as being
genitive and then insert phaasu.m (sg. acc. of phaasu,
'comfort' - masc.). Thus:

Mayha.m saamino jananii bhikkhuniinañca upaasikaanañca
phaasu.m sa'nga.nhi.

My husband's mother attended to the comfort of the
nuns and female devotees.

Best wishes,

Dhammanando