Seems the opinion is dividing between "properly concerned parent" and "meddling bi43h". I say there isn't enough information given to make that call. The OP said:"It seems that everytime I do something whether it be book our band, create some type of promotion material or the latest, post a song to our website that our 44 year old guitar player with over 20 years experience approved, the mom has some kind of problem with it ". I need examples. Take the following:
Scenario 1: OP posts a u-tube video of the band at a gig. In the video, at one point the girl bends over to pick up a tambourine and her thong comes poppoing out of her jeans and is clearly visible on the video. Mom sees video, and objects.
Scenario 2. OP posts the bands latest studio song on the band's website. The girl had done three different vocal takes. Ultimately the Band (led by the OP) decides take #1 is the best and uses that treack for the final version. Mom has heard all three and believes the third take was her daughter's best one, and objects.
To me, clearly in scenario 1 the mom is properly concerned, and in scenario 2 is a meddler. So what are the specifics, OP? What has specifically she objected two and how, specifically, has she tried to turn your band against you?