No, every convertible seat manufacturer sets their own rf'ing weight limits based on their own crash testing and the performance of their seats. Some seats have a maximum rf'ing limit of 30lbs, while others go as high as 35lbs.
It's very important to follow the max rf'ing weight limit provided by the manufacturer. Thankfully most kids don't hit 35lbs before their 1st birthday, and a lot of the chunky monkeys will even make it to 18mos even before hitting 35lbs.
Looking at the weight limits on seats - for both rf'ing and ff'ing modes, when shopping for seats is an important part of making sure the seat fits her child. She should also check that it installs well in her vehicle and that she finds it easy to use. :thumbsup: