Hello there ,
Thanks for writing your query,
As you have mentioned your daughter is seven years old , i would like to inform you that its the eruption phase in childerns where permanent teeth
replace the milk teeth.
so nothing to worry about , loose gums is due to loosening of milk tooth which will exfoliate in future and permanent tooth will replace it.
the gums will heal with time , i would suggest you to go for symptomatic treatment at home like gargling with lukewarm saline water or antiseptic mouthwash like chlorhexidine
Apply oral antiseptic ,analgesic ointments
like dentogel or mucogel topically over the affected area
i hope this helps ,