Excellent question, it all depends on your tort, aahheemmm

(Its 2-4grams a month not week i apologise for my mistake,

sorry )
Well let me try and explain if i can.
I`ve got a 26gram tort so if she puts on 2grams a month comparing that to her body weight thats alot so i`m very very happy.
I have a 41gram tort and if she put on 3grams a months i`d be made up.
i have a 2 year old that puts on easy 4grams a month and it is hard to stop that from getting more so if she only puts on that then i`m happy. if she puts on more then i cut down the food.
I know i`m rubbish at explaining things but i do hope i`ve kinda. The bigger they get the quicker it is and easier it is to put on weight. All my torts sometimes stay the same weight for a month but i am not worried because theyve all had an mot so i`m glad they are growing so slow.
in the wild torts would sleep 9 months and the eat for 3, in captivity they still have the urge to eat but are not neccessarilly hibernated. In the wild theyd take at least 10 years to grow to adult breeding weight or even longer, in captivity its reached in a few years, so if you want your tort healthy with a beautiful completely smooth shell grow it 2-4 grams a month max.
hope ive helped a bit.