One of my family members has a green card since 2004 but only comes to the US twice or 3 times a year for a 3-4 weeks each visit. Can she apply for citizenship now? Is there a specific time she should have lived in the US. She will live permanently in the US after a few years due to business reasons that's why she's not living here permanent as yet.

No, not only she is ineligible to apply for naturalization, but her status is automatically revoked. As a green card holder, she must live in US at least 6 months a year.