[cypher]

It isn't unusual for older hams to lose some weight & eat a bit less but it is important to check her teeth, if they are overgrown & you feed soft foods they will continue to grow & can cause damage to the mouth, palate, nose & eyes eventually.
If you can't check them yourself then you may need your vet to do it.

Porridge, scrambled egg (whole egg) are good for building them up, baby foods & mashed veg are good too, you can soak her normal mix if she does have a problem chewing.
Try not to give too much protein as they need less as they get older & too much isn't good for their kidneys.
If she can manage them small pieces of nut, shelled hemp seeds (in the shell if her teeth are ok) & a few extra flax seeds are good extras.

SKB made a thread on feeding elderly hams with teeth problems here.
Feeding Hamsters with Missing Teeth or Who Are Elderly
There's also a thread on baby food here.