@nadyart I Illustrated my first book through an Irish publisher last year and will possibly be doing a second and third book in the same series. The publisher contacted me and asked me to submit a sample to see if I was the right fit for the project and they liked what they saw I suppose. I must add that it was 14 month after I emailed them my portfolio that I got that response and by that time none of the same images were still in my portfolio. This is why I would suggest getting out there and making contact and even if its a rejection, politely say would they mind seeing new work in 6 month or something to that effect and if possible get feedback.
I think your work is lovely, I would imagine publishers would think the same. It is about you being on their radar when a specific project pops up for them, that they feel would suit you. The first line of the email I received from the publisher was 'We finally have something that might suit you...' I was totally unaware that they were even considering me as I had never got a response after my initial email, only the offer 14 months later.