If the child's foreign passport expires in 2 months

Please note that even if problems arise, the possibility of crossing the border by citizens of Ukraine with internal passports has been extended.

Due to humanitarian circumstances and according to previously reached agreements with neighboring countries, employees of the border agency will allow Ukrainian citizens to pass, including with an internal passport document. This applies to all citizens, regardless of the regions from which they are coming.

But, in fact, there should be no problems, because the passport is still valid.