This is the first time i'm writing on this forum, i play usually mandolin and guitar in a folk duo, having several past experience in other contests, and i want to say hello to everyone.
I am asking help not for me, but for my mate. She have a very nice voice but not very skilled ears.
She is able to sing in a not professional church choir, adjusting the pitch the majority of the note of the song, inside the whole ensemble, being brave to sing, and gaining enough self confidence, just being besides others singers. The contest do not requires to be perfect

I checked her ear skills, also using Earmaster. She is able to have good result about recognizing intervals in first simple exercises. But at the end she lacks on a very basic skill: tuning her voice on a referred played note, on piano or on guitar, or on another instrument, or from a record in a song. I noticed how her have better results on high side of her vocal estension, instead of low side. She even is not easily able to recognize if her voice is above or under a referring note. She also recognize piano notes better than my guitar notes.
Someone could be fully right telling me that my mate (future wife) should give up, and find another hobby. But i want to trust in her for the future, for my musical work. she have a very nice voice and wife is only one... and i would be happy if she could be satisfied with new skills

My question is: apart using Earmaster, how i can "teach" and control her, to make possible her gaining the skill to sing on a referred note, even if she is not able to recognize if is above or under the note?
I know should exist a way.
thank you in advance for any advices...
Luigi