Well first this Hadith (To be find in Sahih al-Bukhari, Sahih Muslim, Sunan ibn Majah, an-Nasa-i, Jami' at-Tirmdidhi) was pronounced in front of a group of Sahaba (May Allah be pleased with him) as the Prophet (peace and blessings of Allah be upon him) uses the plural masculine أَحَدُكُمْ(None of you):
As in many other languages the masculine plural refers to a group of men or a group of men and women or a group of one man and women.
The word "brother" is masculine singular, as we know before emancipation and before using both female and masculine form became usual (both a few decades ago), it was typical to write anything which is addressed to both sexes in masculine form. So "brother" might be understood from a female as "Sister".
Note that: the plural from اخوة in Arabic is used to refer of a mixed group of men and women while اخوان usually refers to only males ("Brothers") and اخوات to only females ("Sisters").
So from a linguistic point of view this already explains that this also applies to women.
Therefore most scholars consider this as a matter of course, so that you'll hardly find any of them (if not directly addressed or asked about it) use the masculine form meaning both sexes and the female form, when they only mean woman and if they mean only the men they would add this by using the word الذكرa-dhakar male to point it out.
So one can understand this hadith as to be addressed and to apply to "sisters" as well as to "brothers"!
On the other hand, when reading the Qur'an you sometimes read an expression addressing both sexes for example the Muslims and Muslimat (Muslimat) (apparently mentioned only once in the whole Qur'an) or Mu'mins and Mu'minas (Mu'minat) or Munafiqin and Munafiqaas (Munafiqaat)...
This might be an affirmation or confirmation to make sure that both sexes are meant, because of the importance of the content of the upcoming Verse!
This is only my understanding and opinion of this issue and may need some more analysis to confirm whether it is right or wrong! But i can't recall any hadith which addresses both sexes similarly!
And Allah knows best!
