Preserving Minecraft games, add-ons, etc. on Kindle when logging out of MS account

Simple question, but long-ish set-up.

1) We bought my granddaughter a Kindle Fire so she could play Minecraft. After a while she wanted to play it with her uncle, so she had to have a gamertag. You have to get that within your Microsoft account. She didn't have one, but I did, so we used my account to get her a gamertag.

2) During this time we occasionally got her add-on items for two or three dollars. Since it was a Kindle, which is an Amazon product, all those add-ons came from Amazon.

3) Her Kindle went tango-uniform for some reason, so we got her another one. Magically, all her add-ons and games eventually populated to the new Kindle.

4) Now she wants me to join the game, so I bought Minecraft for Windows ($39 versus $7 for her Kindle version).

5) So I have to get a gamertag, but her's is already linked to my MS account.

6) So I create a Microsoft account for her and put it into my family group, thinking that there will be a way to transfer ownership of the gamertag, or something like that. No can do, of course. I can ditch that gamertag, but it won't be available to pick up for 37 days, and then anyone can get it.

7) Fine, but when I try to create a new gamertag from within her Kindle, that feature is unavailable to her. I can log off the MS account from within that same section of Setup so that I can log in to her MS account, but a warning appears that all her coins, stored games, etc. will be lost.

8) Now, it occurs to me that, since all her add-ons, stored games, etc. are linked to Amazon and not Microsoft, they will all magically populate, as they did before, even though she can create a new gamertag in her MS account.

Am I right?

Thanks and regards,

Richard White

:)