My little girl is 11 months and a week old now ...

My little girl is 11 months and a week old now and is a great eater. She seems not so interested in her bottles though only drinking around 120mls 3 times a day. When is it ok to start her on bottles of cow's milk? She has cow's milk on her 1 1/2 weetbix in the morning and in her mashed vegies and such. She also already eats some cheese and butter. So I figured it would be ok but wanted some other opinions please. I have been told to start on one bottle of cow's milk in the morning for about 2 weeks and wean of the formula from there. Thanks for your advice and opinions.