Dear Zenith
Lao Nationals generally do not require an entry visa for short social visit or business trips to Singapore, so long as the period of stay does not exceed the short-term visit pass stamped by ICA on her passport at point of entry. She may wish to take note of the entry requirements as listed on ICA's website http://www.ica.gov.sg/page.aspx?pageid=95 to facilitate a smooth entry into Singapore.
Should your friend need to extend her short-term visit pass, she can follow the steps at the following website http://www.ica.gov.sg/page.aspx?pageid=180&secid=178 to apply for extension up to 89 days from the date of entry into Singapore.
Best regards,
Singapore Embassy