Yes, just ask her, "I was wondering if you are Sunni or Shia"
The Sunni means you follow the Sunnah (the sayings and teachings of the Prophet Muhammad pbuh). She is most likely this type. The Prophet revealed to us this knowledge about sects 1400 years ago
[006:159] Verily, those who divide their religion and break up into sects (all kinds of religious sects), you (O Muhammad [Peace Be Upon Him]) have no concern with them in the least. Their affair is only with God, Who then will tell them what they used to do.
(V.6:159) It is said that the Prophet [Peace Be Upon Him] recited this Verse and said: "These people are those who invent new things (Bid'ah) in religion and the followers of the vain desires of this Muslim nation, and their repentance will not be accepted by God." (Tafsir Al-Qurtubi)
[It has been narrated in the Hadîth Books (At-Tirmidhi, Ibn Mâjah and Abu Dâwûd) that the Prophet [Peace Be Upon Him] said: "The Jews and the Christians will be divided into seventy-one or seventy-two religious sects and this nation will be divided into seventy-three religious sects, all in Hell, except one, and that one is: on which I and my Companions are today, i.e. following the Qur'ân and the Prophet's Sunnah (legal ways, orders, acts of worship, statements)."]
Peace Be With You