Thought I would help you out with a few look ups in the indexes to start you off - but I soon got confused!
Here is the birth of Emily Bickerdyke in 1918
Jul/Aug/Sep 1918 Emily Bickerdyke, mothers maiden name Gaines, Leeds area ref 9b 521.
I was going on to find the sisters, when I saw that the mother was Potts nee Bickerdyke - is this the mother of these 4 girls?
So were Emliy, Emma, Ivy and Lily childen of Lily Potts nee Bickerdyke - in which case that will not be Emliy's birth as she would be a Potts?
But you are looking for a Bickerdyke? Yep - i got confused!
Or was Lily firstly a Gaines (as per birth entry) then married a Bickerdyke, then remarried a Potts?
Seconldly, Lily Louisa looks like she was born about 1888. I'll have a quick look for her birth under Bickerdyke and Gaines