Filing I-130 for PARENTS

[mali404]

Hi,
Can someone please suggest me with my situation.
My parents are visiting me in the US on visitor visa. My sister is an US citizen but I'm in H-1B. However, my parents didn't mention anything about my sister in OF-156 form. Again, visa counselor issued visa assuming that my parents would return to their homeland after visiting me.
Now, my question is:
Q. Is it okay for my parents to file I-130 based on my sister's status within their first/second week of arrival and wait till they get their approval?

[immihelp]

After their visitor visa expires, they would staying illegally.

So it is better to leave the country and wait there.

[Tsue123]

INS might suspect your intentions if your sister applied for them while they are in the US.