Worried about getting through the US border after being denied once before

About 11 months ago in January my girlfriend and I were trying to get into the US from Canada, the country she was residing in at the time, but she was denied entry for not having strong ties to Canada and had to return to her home country of Singapore.

It is now 11 months later and she would like to come visit me in the US early next year, but she is worried that her previous denial of entry will raise flags and cause her not to be allowed in again.

A few details about her current status:

- She does not own any property in Singapore but she does have a job within a family business

- She will have a return flight already booked before entering the US

- She will have enough money in the bank to show she can financially support herself for the duration of the trip

- The trip will be a few days long but no more than one week

- Maybe unimportant but she will be traveling with 4 of her family members

Her main concerns are the fact that she was denied entry once before and that her job would not be viewed as a strong enough tie to her country since it is a family business and she didn't sign any contracts to be employed there. She is on the company payroll though.

Will she have any trouble getting into the US with her current status?

Any input and personal experiences would be greatly appreciated.