The 'Grammar Focus' table in Lesson 2 lists 'crying girl' and identifies 'crying' as working 'as an adjective'. In 'I saw a crying baby', 'crying' modifies 'baby', acting as an adjective, thus it is a present participle.
Class 6 › English Grammar and Composition › Chapter 5: The -ing form of Verb: Gerund & Participle › Topic: The -ing form of verb: Present Participle
Aligned to the NCTB national curriculum.