"My daughter is 17 years old."
Using 的 is the general rule for possessives. Not using it is a special case. If the possessor is a pronoun of 1 syllable (我你他她它) and the thing they possess is something "relational" -- something that you almost always use a possessor with (媽媽，爸爸，亥了，maybe even 朋友), then you can drop 的.
Sentence is subject+predicate
是学生 is a noun-based predicate, and nouns use 是
吃饭 is a verb-based predicate, so is 爱吃饭
高兴 is an adjective-based predicate
很高兴 helps to show that 高兴 is a predicate, not the start of something longer
十七岁 is a predicate, don't ask me what kind, but it's not a noun
要 is definitely wrong, maybe you mean 有？