Hi Elfi,
I'm a speech language pathologist who will be moving to Buenos Aires next month. I specialize in pediatric speech therapy, and have worked with children your daughter and son's ages with similar backgrounds. It sounds like your daughter would benefit from articulation-based therapy, and that your son needs a speech therapist to collaborate with his audiologist to determine the best way to facilitate hearing and speech and language development. I've spent the last two years working with two and three year olds specifically, and can help you work on the skills you mentioned. Feel free to contact me via email: ilanajoy.g@gmail.com if you have any questions, and I'd be happy to help!
Kindly,
Ilana