Hello,
This condition is quite common and there is nothing to worry about.
However, if the new tooth (permanent) is getting stuck behind the lower teeth on biting, then removal of milk tooth is definitely advised.
Or if it's been over 6 months since the new tooth has erupted , then the dentist may suggest extraction.
Next Steps
Get a dental check up for a better understanding of the position of tooth.
Health Tips
Milk tooth extraction if advised, can be done painlessly and gently. Do not worry.