Great start! Always nice to see a new writer tipping [his?] toes into the waters of content creation.

I really like some of the whimsical descriptive language you used here (like a "literal handful of fairies") and I think you do a good job of conveying the imagery and setting the scene. You even did some things I haven't read before, like describing the cracking of Thistle's joints as she expanded. 

I'm looking forward to future chapters, as I expect we're getting more character work and dialogue between James and Thistle soon. Based on your comment about the story being five chapters, I assume you already have an outline. I'm wondering where things are going next, as I see this is a gentle story, but it's also rated R, which is a rare combo. Based on Thistle's nudity and the rating, I suspect things might get smutty, but at the same time I don't see the usual smut tags for vore, insertion, entrapment, breasts, etc. and that doesn't seem set-up yet (though there are still at least four chapters to go, so who knows?).

None of that is intended as a criticism or a suggestion at all; just the musing of an intrigued reader and fellow author. I'm probably overanalyzing a modest introductory chapter, but I'm curious how many of these details will actually come back in the story or simply serve to immerse the reader in the world. Will Thistle revisit the other fairies? Perhaps she'll wander to the village? And what is to become of the rest of the growth potion, as she supposedly only consumed a little of it thus far before returning it, meaning there is a whole cask of potion in the apartment that I suspect she'll outgrow soon. I wonder if it has any potency when applied topically, or if it can be applied to other organic matter (like leaves) to make her a new dress. 

Anyway, I don't actually anticipate any of that stuff happening. This seems like it's set up to be a short, well-contained story between two characters. If you have an outline, I strongly encourage you to stick to it and tell the story you want to tell. I just like to speculate and I find other authors tend to appreciate the attentive insights of their readers, even if they are completely off-base. XD

Great set-up chapter. Looking forward to more.

P.S. I would encourage you to reformat this story with "shift + enter" spacing instead of the regular "enter" spacing, as it makes the text much more compact while keeping paragraphs distinct. It's a little thing, but I think it looks better and minimizes scrolling. GW can be a real pain to format on, so I sympathize.