She's losing her appetite

Hmmm... it's coming to a week now - Leia seems to be losing her appetite. She refused to finish her "moi" (porridge) and milk almost on her every meal. She used to drink at least 7 ounces of milk in 2.5 hours time but now... she couldn't even finish her 6 ounce milk. 

I'm getting a bit concerned. Could it be due to teething? She's coming to 13 months old and yet, there's no sign of sprouting teeth. 

Tried giving her other new type of foods like bread, biscuit, oats, pears but she doesn't seem to be able to eat a lot. That includes her favourite biscuit - Jacob's Weetameal. She could only finish quarter or maximum half of the biscuit when previously, she could finish one whole at one go.