Divorce- contest & prevent

My wife started living separately 3 years back, and did not respond to any conciliation efforts by me. She also took our young daughter along with her. Now suddenly a Lawyer has sent me a notice on her behalf asking for Divorce by Mutual Consent; and that I should let them have my response in 2 weeks, else they'll decide their course. I am still looking for a professional counselling and conciliation, with definite NO to a divorce. Question 1: Should I be responding directly to her lawyer myself (I can write quite well), or necessarily engage a lawyer to respond for me in legal language; Qs 2: If I respond directly, can I reiterate the facts of our long happy marriage (20+ years), my wife's abrupt walkout and not providing any opportunity for conciliation, keeping our daughter with her without any mutual agreement; and also requesting her lawyer to guide her first towards a Professional Counselling process? 3. In case you can share a draft response with legal aspects for this purpose, it would be additionally helpful. Thank you.