I am the same as you, so slow in Serbian Cyrillic! But from what I have read, the native speaker should be speaking their own language with the child. But it doesn't hurt us to try and improve our Srpski! I have both English and Srpski books here. I brought the English ones from home. English books here are expensive, but I haven't shopped for them at the fair or in BG. I have a Kindle fire for me and my little one. It is great for getting apps and games for her in English and even children's books! I use it for books in English. It is Priceless if I ever have the chance to read... (Pretty much never!) 
If you could speak Serbian with your little ones with the hubby. And he speaks Serbian with them, they will be golden by the time they are 5. If you want to speak Thai with them as well, they will pick it up too!
I am happy you like my blog. 