Please tell her not to worry.
Unless the child is at risk in her home - which clearly she is not - there is no chance of the child being removed form her care.
These threats are designed to scare her - the priority for the court is the needs of the child - not those of the father
She should tell her ex that it is time that a regular pattern of contact is agreed and that she wishes to discuss matter suing Family mediation
If he refuses then she shoudl offer a regular pattern of contact - say alternate sundays - and make it plain that other than those times the child will not be available.
I hope that this is of assistance - please ask if you need further details