Can I get a family extension in Thailand after my Non O visa expires if I have a re-entry permit?

On a retirement extention from my Non O and it expires in July and i am not renewing. Taking family to UK in Aug and getting a new multi entry O and will do the visa runs every 3 months. Some time ago i asked immigration if i could get a months ext in July but they said only 7 days, so i have booked a flight to Cambodia next week and plan to come back on 30 days then another 60 days from immigration in Jomtien, but since i booked my flights i have read about people getting family extentions based on marriage and children. Did i misread or could i do that once i return if i get a re entry permit. My next 90 day report is 24 June, but my flight is 14th and returns 17th.