It is about the same. If they reject your REP renew.
"If you leave Singapore or remain overseas without a valid REP, you will lose your permanent residence." Then you will have to go thru those hassle to apply PR.
https://www.ica.gov.sg/PR/reentry/pr_reentry_apply
If have housing and have baby, mostly people say the chance is very high. Less than 1 year can get. Contribute~
Maybe bro in the process of the application should live normal and not anxiety to get the status. Get your house. Have good family. Have baby. In a year, let her stay in SG about 9 month. Every 3 month go back thailand for a month(they will monitor her activity).
Like this you will feel much better.