Tirimdhi 3690-The Lady Who Beat The Duff And Sang In Front Of The Prophet (SWS)
If she took an oath of singing a song on return of the prophet (SWS) then it definitely means she was not a first time singer, but a routine singer who had good grasp on singing. Please read below another variant of this hadith which mentions presence of Abu Bakr (rta) and Umar (rta): https://sunnah.com/tirmidhi:3690
The variant of Tirimdhi that I shared above clearly mentions this fact: فَقَالَتْ يَا رَسُولَ اللَّهِ إِنِّي كُنْتُ نَذَرْتُ إِنْ رَدَّكَ اللَّهُ سَالِمًا أَنْ أَضْرِبَ بَيْنَ يَدَيْكَ بِالدُّفِّ وَأَتَغَنَّى “She said: O Messenger of God, I had vowed that if God returned you safely, I would play the tambourine and sing in front of you .”