Does the Turkish count in the IB-designated world languages not otherwise specified?
The Turkish would be a plus in terms of college apps, IMO, because of the interest factor. If your kids want to continue in Turkish, they should screen the colleges’ foreign language offerings because that would be a limiting factor. How it would count as an exemption from college foreign language requirements would vary.
My son had an issue in high school with foreign language as well. We moved from one state to another. He had two years of German when he entered junior year at his new school. The school did not offer German as a foreign language. It had a three year foreign language requirement for graduation, as did the state Regent’s requitrement (NY). He took a third year of German on his own through an after school German program he found, passed the Regents exam, and the school gave him a pass because of that. So, yes, these quandries do happen