You might see terms such as dependent possessive pronoun, possessive determiner or possessive adjective.
你可能会看到像从属所有格代词、所有格限定词或所有格形容词这样的词。
可汗学院公开课：英语语法
The second member of this confusing trio is their T-H-E-I-R which is a possessive determiner.
这个令人困惑的三重奏的第二个成员是他们的 T-H-E-I-R，这是一个所有格限定词。
英语百科
Possessive determiner
Possessive determiners constitute a sub-class of determiners which modify a noun by attributing possession (or other sense of belonging) to someone or something. They are also known as possessive adjectives, although the latter term is sometimes used with a wider meaning.