Gerund: "Having a routine" as the subject of the sentence, the use of this gerund increases the complexity and formality of the sentence.
Relative clause: "that helps them develop time management skills" is used as a relative clause to modify "routine", adding detail and complexity to the sentence.
Present participle as adjective: "structuring their day, balancing schoolwork with playtime" These present participles are used as adjectives to describe how children organize their day, increasing the complexity and amount of information in the sentence.