Her menses ended but there is still some blood in the urine; should she fast?

Praise
be to Allah

The end of
menses can be determined by one of two signs:

i.                   

Emission of the
white discharge, which is well-known to women.

ii.                 

Complete
dryness, so that if a piece of cotton or the like is inserted into that
place, it comes out clean with no trace of blood or yellow on it.

Al-Baaji said in
al-Muntaqa Sharh al-Muwatta’ (1/119): What is usual when the menses
ends is two things:

[The first is]
the white discharge. ‘Ali ibn Ziyaad narrated from Maalik that it resembles
semen. Ibn al-Qaasim narrated from Maalik that it resembles urine.

The second is
dryness, which means that when the woman inserts cotton or a piece of cloth
into her vagina, it comes out dry, with no trace of blood on it. What is
normal for women varies; some of them usually see the white discharge, and
some of them usually see dryness.

So for a woman
who usually sees one of these two things, and she sees it, then that is
deemed to be her tuhr [becoming pure when menses ends]. End quote.

If she does not
see the white discharge, or does not become completely dry – rather there is
still some blood, even if it is little, or there is yellowish or brownish
discharge – then she is still menstruating, and it is not permissible for
her to fast. You have to make up that day, but there is no sin on you,
because you were following the Islamic command of not fasting at the time of
menses.

The basic
principle is that the bleeding that occurs at the usual time of a woman’s
menses is menstrual bleeding, so long as it does not go beyond fifteen days;
in that case [if it lasts longer than fifteen days], then it is istihaadah
[irregular, non-menstrual vaginal bleeding] according to the majority of
scholars.

It should be
noted that menstrual blood does not come out of the same place as urine; but
perhaps what you meant is that you saw the blood, or you noticed it, when
urinating.

And Allah knows
best.