It is normal for a 7 year old to have wetting accidents and the occasional poop accident but if the accidents occur too frequently then there could be a health issue that needs checked out.
Lots of kids including 7 and sometimes even 8 year olds will have the occasional pee accident in their pants when they are too busy playing or don't want to stop a game etc to go pee.
Although if the kid or 7 or 8 year old child continues to pee in their pants or it happens everyday or all the time then they could have a bladder infection, nerve issues with their bladder or something else may be going on.
So if the 7 year old continues peeing their pants you should take them to the doctor to get tested for possible health issues that are causing the bladder problems.
If the wetting accidents or poop accidents happen too often then you should have the 7 year old wear a pull up or diaper just in case.
Even when they are wearing a diaper they can easily remove the diaper to go pee or poop and then put it back on.
Wearing a diaper is much better and much less embarrassing than wearing wet pants and having to clean up pee off of floors, furniture, bedding etc.
They make diapers in all sizes.
If your 7 year old needs diapers then your 7 year old will most likely fit into a size 7 diaper such as Gentle Steps size 7 diapers from Dollar General.
These diapers are not babyish like some other diapers as they are mostly plain white but with a wetness indicator and a small landing strip with pictures of animals.