Hi Lisa,
No I'm afraid I don't have an exact date. Its a bit of a long shot really. Ancestry came up with a hint which suggested the NY Passenger Lists but my membership doesn't allow me to view. I have Percy William on an 1891 census in the UK, but then no trace. I do know the family was split up when the mother died, so I may be completely wrong to chase this hint. Please don't go to any time or trouble if its not obvious, but thank you very much for getting in touch.
Best regards,
Anne