All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu 'alayhi wa sallam, is His slave and Messenger.
There is no harm if the husband sends university fees to the daughter of his sister in-law electronically by himself.
A man is not sinful if he speaks or corresponds with a non-Mahram woman when there is a need, as long as one is safe from temptation.
Allah knows best.