Of course Phoebe is mentioned as a servant of the church.
Romans 16:1 commend unto you Phoebe, our sister, who is a deaconess (esp. a Christian teacher , a minister, official servant) of the church which is at Cenchrea.

This statement came from the Apostle Paul, the definitions from a Greek-/English dictionary. 

  2: That ye receive her in the Lord, as becometh saints, and that ye assist her in whatsoever business she hath need of you: for she hath been a succourer of many, and of myself also.

  The word minister is also defined in the Greek dictionary as deaconess, teacher or PASTOR.  It is inferred that she was the overseer in her position.  This word servant, or minister is the same word rendered minister when attributed to the Apostle Paul and to Jesus Christ, Himself, as well as many other male ministers.  The Apostle Paul told the saints to assist her in whatever she needed them to do, for she was a succourer.

Phoebe was an guardian, a servant, just as Jesus girded on the towel at Passover, and washed the feet of the disciples, he explained to us, if any will be great among us, they must be a SERVANT. Matthew 20:26. She was a servant of the Gospel, and church of the Lord Jesus Christ. She was also according to Greek definition, a guardian and protector.

The last verse in Roman, chapter 16, though not numbered is found in the original Greek language.  It reads: 

  "To (the) Romans written from Corinth. By Phoebe servant (one in God's service, a minister, deaconess; Greek English New Testament Lexicon) of the in Cenchrea assembly.