Thanks for the responses - some sensible and some not so (no more banjo jokes please or babies are bad stuff - they happen so get used to it)

Here is a summary of the sensible tips :-

Be careful with volume as childs ears are sensitive
Look in their eyes while you sing ( do that already)
Pots and pans make fine instruments
Toy ukelele and bodhran are fine to start with (got both already !)
Play CDs at bedtime
Allow to touch and play with instruments but be careful with strings (do that already)
Don't force it (prob best advice)

Thanks for advice.

Jiggers