Lying in Family Court

I was wondering if any one had any experience of extreme lying in family court and any ideas on how to get the court to deal with it.

Long storty short , after a one night stand which resulted in pregnancy, my OH cared for his twin boys 50/50 from birth until they were two. When they were two her contacted their mother and told her he had met someone (me) and we were planning on moving in together soon. He was giving he the head up that they were going to be meeting me that week.  Mother repsonded saying that until the children were older they were not to meet partners, and on that basis stopped contact. Did not see the children for 5 months while it went through court.

Fast Forward 12 months, stil a nightmare, contact order in place but already had two enforcement hearings as mother is not complying. She is looking at unpaid work next time the judge said. BUT then last week she via her solicitor) submitted a C1A to the court stating that we neglect the children and have sex right in front of them whenever they come to visit (absolute nonsense). She also reported that one of them lost over a stone in four days while he was staying with us (they only weigh 2 1/2 stone in the first place!)

Luckily we have medical records and things and can prove she is lying. She has messed up becuase she told the court that a health visitor had assessed the boys as not suitable for contact with us because it was so distressing for them and we are so negelctful, yet the health visitor has confirmed it in writing to us that this never happened and that they have not visited the twins in months.

So thats the bare bones of it. How have other people dealt with this kind of accusation in court? and what was the outcome? 

Any ideas would be greatly appreciated!!!