Praise be to Allaah.
If there is any illness or defect that could affect married
life or it could put one spouse off the other, it must be disclosed and it
is haraam to conceal it.
Ibn al-Qayyim (may Allah have mercy on him) said: Every fault
which puts the other spouse off, so that the purposes of marriage, namely
compassion and love, cannot be achieved, mean that the spouse has the choice
of annulling the marriage. (Zaad al-Ma’aad, 5/166)
See also the answer to question no.
Bedwetting is a fault that the suitor must be told about, but
if your sister has recovered, or there is the hope that she will recover
soon, then you do not have to inform her suitor.
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have
mercy on him) was asked: There is a man who proposed marriage to a woman,
and it is known that this woman has a physical defect, but this defect is
hidden and is not obvious, and there is the hope that this defect may be
cured, such as leprosy or vitiligo. Should the suitor be informed of that?
He replied: If a man proposes marriage to a woman who has a
hidden defect, that some people know about, if the suitor asks about it, it
is obligatory to tell him; this is clear. If he does not ask about it, then
he should be told about it, because this comes under the heading of sincere
advice, especially if there is no hope of it being corrected or cured. But
if there is the hope that it may be corrected or cured, then it is less
serious. But there are some things that may be cured, but the process is
slow, if indeed it is even possible, such as leprosy, and to the best of my
knowledge I don’t think it can be cured completely. Therefore a
differentiation should be made between that which may be curable quickly,
and that which is curable but will take some time.