1. Women such as Mary and Mother of Musa received wahy (revelation) but only regarding their child’s outcome. Did women ONLY receive personal revelations?
2. Why aren’t there any women messengers?
No. Prophets of God in general received several forms of revelations. This included but was not limited to angelic communication, dreams and direct inspiration.
The fact is we really do not know if there were women messengers or not. The Qur’an states that all nations at one point or another received prophets or messengers who would administer religious messages to their respective communities. The messenger or prophet was always appropriate for the times and circumstances of the particular nation, hence, if a certain nation required a prophetess because that was the set up of the people then surely God would have taken account such a need. You may be interested in reading, “Women Prophets” in one of our previous replies.
I hope I have clarified the issue.
God knows best.