Most lawyers can apply for finance with a lending company that specialises in family law lending, against any assets you have even in joint names. 

So I had a house in joint names. A caveat was placed on the house and a loan taken out with a cash payment to myself aswell. This is how I was able to fight and pay for a divorce coach. 

Best thing I did, also remember you don't have to reply to everything their lawyer sends. ONLY reply to actual negotiations and not the dribble attacking you. They are just trying to run your costs up and wear you down. 

Always remember you can't control someone else's behaviour, you can only control how you react. 

Bella x