i have an inventory system that will add childs when collect objects into a vertical box and when i close the widget and open it , all the childs reset like it never got added so i thought a save and load would fix this issue and even if i didnt have this problem i would still make save and load for it because am making a survival game could any person asist me with this idk how i will save the widget childs.
Sure 
, one of the solution would be to use game instance, from there you can store your variables like itemID, array of slot etc…
That way whenever you open your widget, you can load data from your game instance for getting the right number of slots and thier itemsID.
You can also just hide/unHide the inventory ingame, this make it quicker to display but consume memory.