how can I translate the theme in the child theme?

I have installed seopress theme and have created a child theme,
what I want to do is this: I want to translate the seopress.pot and po files to my language, the problem is I cannot do my translation inside the child theme! I have to put my translated po and mo files inside the main theme’s language folder! why?
do you have any solution for me to make it work inside the child theme’s language folder?

I mean it only works when I put the translation files inside the main theme’s languages folder but does not work when I put them inside the child theme’s language folder!