Greetings, sir/madam.
I would like to offer you my singing, songwriting and musical skills. I have more than 10 years of experience in these fields and especially when it comes to nursery rhymes, as I've done more than few times most of these songs that you need. Duration and price depend on whether you need only vocals or need the instrumentals also.
My skills cover singing, mixing and playing the song, if necessary, so please contact me if you're interested, I would be more than happy to assist you on this project.
Best regards,
Bojan