Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that your daughter is suffering from viral infection caused by 
Herpes virus and due to which there is formation of small painful sores on the roof of her mouth along with 
fever and the condition is known as HERPATIC 
STOMATITIS..
As she has a viral infection so antibiotics are of no use as antibiotics can only cure bacterial infection..
Consult a Paediatrician and get her evaluated..
You can give her Fepanil liquid as it will help in reducing fever..
Feed her with cool and bland food as it will prevent irritation in her mouth..
Give her plenty of water and cool liquids as it will relieve pain..
The paediatrician can also prescribe her with 
antiviral oral medication like 
Acyclovir as it will reduce the duration of infection as well as prevent outbreaks..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora..