Teaching married children is the most challenging of all.  Perhaps the best counsel is from D&C 121:  41 which states:

No power or influence can or ought to be maintained by virtue of the priesthood (or by virtue of money), only by persuasion, by long-suffering, by gentleness and meekness, and by love unfeigned;  By kindness, and pure knowledge, which shall greatly enlarge the soul without hypocrisy, and without guile—

From a gospel perspective:

• Teach by example, and  
• Be a good example of a wise financial steward that has his/her priorities in order.

Things to do and teach with this age group:

• Realize that retirement planning comes first: helping children with money problems comes second
• Minimize discussions of what children and grandchildren will inherit or receive as gifts
• Minimize gifts of cash to adult children as part of a negotiation strategy
• Help adult children recognize when they need financial help and to accept it graciously
• Stay out of your adult children’s family matters, and
• Assure your children that they will not receive any inheritance until they have established a mature, disciplined, and adult lifestyle and profession.