Babies should start tummy time between 2-3 months old, but I've seen where some parents do it as early as 4-6 weeks. She may be holding her head up a little or steading herself, but not what is considered holding her head up for tummy time. You'll see as she progresses over the next couple of weeks a huge difference. I found this information on Tummy time. A parent should introduce “Tummy Time” when the child is between 2 to 3 months of age and when they are able, for the most part, to hold their head up against gravity (even for short periods of time). Children should ALWAYS be supervised by an adult while in this position. Even newborns can benefit from tummy time! Parents should be encouraged to have their babies lie on their chest, when sleeping or dozing; infants tolerate being on their stomachs better when they are placed in a more upright, slanted position. They can also be “propped-up” with a towel positioned under their arms.Infants should be provided with "Tummy Time" at least once daily and more frequently if possible. Dr. Stacey O’Connor, an osteopathic doctor with IHA Livingston Pediatrics in Brighton, tells her patients to put their babies on their tummies for 10 minutes three times a day after they are six to eight weeks old.