Never give much thought to everyone´ s view about a lady´ s tonsure. The view of husband and parents is good enough. Just do not care about others´ views and just laugh it off.
Venidaan:- Always to be performed by a married lady in the presence of her husband only once in her life time. First the husband should get his tonsured (with kudumi). The wife should take bath and wear a new saree. She should wear sindoor, kumkum etc. The husband should comb and braid the hair of his wife and put flowers in it. Then with a set of new scissors cut of a predetermined length of her braid and hand it over to her. Some shy women cut off just a few fingerwidths while one cut off till close to the head. The lady should do pooja to the cut braid and ceremonially leave it into the Triveni sangam with mantra. The pandit on the bank will advise on this.
After that she can come back to the bank, sit there cross legged (her husband must sit watching her) and get her head completely tonsured (without kudumi) by a barber. She should give daan to the barber, bathe again in the river with the saree she had worn and further wear a new saree. The sarees need not be costly.
As for myself, my hair is about two years old (my last tonsure was in 2009) that is, about 15 inches long. I will be doing venidaan at prayag in 2013. By then I expect my hair to be about 2 feet long. Afterwards, no more long hair for me - only short boycut and Tirupati gundu.
Is your wife a housewife or employed?