The easiest way to allow others to update your tree is to build an online family tree.
If you publish from FTB, neither you nor your sister can update it online.
If you are using FTB and want to continue to do so, you can send your tree as a package to your sister(she needs FTB on her computer) and she’ll make changes and send you the package back which you can publish later on.
If you have built a tree on FTB and want to now convert it to an online tree publish it on the site then export it to your computer and then import it back from the site.
I hope this answers your question.
If you have any questions about the above processes please feel free to contact me at firstname.lastname@example.org
If I am using FTB to maintain my family tree, when I upload to the family site, I now have two different trees, one on the family site and one on FTB. There is no way to update the FTB tree with changes from the family site or to update the family site with changes from FTB.
The only option is to upload a whole new tree from FTB to the family site. Or to download the tree from the family site as a gencom, and then import the gencom into FTB. The problem with that, of course, is if some changes were made to the tree on the family site and some changes were made to the tree on FTB, there is no way to capture both sets of changes, and it may not be possible to figure out what the differences are between the two trees.
Yes, this is the situation right now, the best way to build your tree is to first of all to decide where you want to base your tree! Either on FTB or on the family site.
If it is on the family site then every member can work on it and you can build your tree together but you will not be able to use some of the features of FTB that we do not have on the family tree.
And if you decide to work on FTB then it will only be you who can make changes on the tree, by editing it on FTB, but you can still publish your tree to the site and everytime you publish you basically update the existing tree, it's not a new tree every time. And your relatives, looking at your tree can give you suggestions as to what to add and whom to add to your tree.
Please feel free to write back if you have any other questions.