Find Ancestors

Trying to find two half siblings of my fathers. They were born in the Warrington area and would be over 60 their fathers name and my grans married name was Kelly but she left him and the children and married my grandfather an Irish man Peter Shortt who could have been known as many different names like Paddy, pete, Huey etc. My granmothers name was Emily Louisa Whale, but she may have been known as Louisa, She had one brother and was brought up by her aunt in the Warrington area. Her father was a Dutch sailor and that is all I know. I am keen to get in touch with any family members from my fathers side as we know nothing about the two children she left behind and all our relations from then on. If you know anything about them or need to know anything about my grandmother I will find out from my dad's sisters who are still alive and well along with 3 of his brothers. Unfortunatley we lost our dad this year to Lukemia and it is this mystery and not knowing part of my family that I decided to try to get in contact with a part of the family we know little about.