Hello there, its very difficult when theres no history of the patient available, nonetheless I'll try to help you as much as i can.
Your mother should take
Vitamin B complex available as a single capsule like Becosule if she is having oral ulcers or chelitis.
Its imperative to know the cause of the disease rather than just treating the symptoms.
For increasing appetite she can have Elixir Neogadine 10ml at bedtime.
Next Steps
Consult a doctor if you have any further questions. i myself am available here on practo