Fructose Intolerant 3.5month old baby

Hello, my daughter is 3.5months old and has been diagnosed with Fructose Intolerance via a DNA analysis. She hasn’t yet been exposed to any fructose since I’m still breastfeeding but soon we need to start solids and I just wanted to learn a little more about the condition…

Since she had the DNA analysis and is lacking Aldolase B that means she has HFI right? Now are there different levels of intolerance between HFI individuals or everyone with the condition has to have a fructose free diet?

Please advise… anything will help.