I think hole in ear, you mean hole in the ear drum.
There is no need to worry. Usually it heals by itself after sometime of stoppage of ear discharge
unless hole is very large. Generally the hearing is not affected much, unless it is very large. But if the other ear hearing is fine no need to worry.
But one thing, she may get ear discharge off and on whenever she gets common cold
. Catching cold is common in children as their immunity gradually develops.
By the age of 10-12 yrs if the hole does not close by itself (Usually large hole) surgery may be required to repair it.
Prevent entry of water to that ear by keeping a cotton plug smeared with vaseline during giving bath.
When her cold lasts more than a week show to a doctor
If she is getting very frequent colds, consult an ENT specialist