My daughter (11) has been really struggling with lower C# on her alto sax - she can play lower C and lower D nice and strong with any dynamics and articulation, but somehow the C# is a hit-or-miss affair for her. Her teacher suggested relaxing the embouchure a bit and putting more mouthpiece in, but it didn't seem to help much. Any suggestions will be much appreciated, but please note I am not a musician and I do not play any instrument myself so as plain English as possible, please. :-)
Also, any exercises you'd recommend? We've been trying interlaced scales (C, C#, D, C#, E, C#, etc.) and simple tunes so far.