Plural marriage and fair treatment of co-wives, Dought & clear, - * Going to his second wife, who lives with his mother, on a day that is not hers

A person has two wives; one of them stays with his ill mother to look
after her. Is it permissible for the husband to visit his mother to
see how she is for little while, and then goes to his other wife (who
has the right of the day)?.
Praise be to Allaah.
It is permissible for the husband to go to his second wife during the
day if that is for a reason, such as checking on her, or giving her
her maintenance or taking something from the house and so on.
He may also be intimate with her however he wishes, without having
intercourse, but he does not have the right to spend a lot of time
with her.
But if that is at night, then it is not permissible for him to go to
her unless it is necessary, such as if she is very ill, or there is a
fire and so on.
This has been discussed in the answer to question no. 106513.
But it seems that you are going there to visit your sick mother, and
asking about her is permissible by night or by day, so long as your
intention is to visit your mother, and not to visit your wife.
In this case your visits should only be as long as necessary, and when
you have achieved your purpose of checking on your mother, taking care
of her, helping her with what she needs and comforting her, then you
should leave and go to your other wife, and you should not stay with
your mother for a long time when there is no need for that.
And Allaah knows best.