how Long can you wait to file for parents after naturalization

[Mama T]

My sister will be a citizen by end of month . How long can she wait to start process to apply for green card for mom to come join her in America

[newacct]

She can wait as long as she wants, or she can file immediately.

[honeydee]

I started mine almost immediately

[Mama T]

How was the process . We want to start tomorrow . She had it on Monday