Hello...
I understand your concern, every area of our cavity cannot have same size and density of gums.
Everyone usually has little less gum in the lower front area, if you don’t have any problem right now like if the gums have receded from teeth, sensitivity, cavity etc then don’t worry.
For proper care of your gums you should brush twice daily, do flossing, do warm saline rinses, massage your gums for 1-2 min with finger tips, eat healthy, take good amount of vit C and various other vitamins and minerals and visit a dentist every 6 months for a routine dental check up.
Health Tips
Maintain a good oral hygiene