Is Rarity a millionaire? Three boutiques.

[Red Cedar 1,408]

Unfortunately, it's implied that Sweet Apple Acres isn't too financially well off, to the point where one bad season could end up bankrupting the Apples.

 

Personally, I hate this implication, but it's there... 

Truth is, many farms are like this but it usually takes more than one bad year to completely wipe them out. They've also toned that down somewhat of late. In any case, even if it were to come to that, there would be quite a bit left over from the sale of the farm that Applejack could probably downsize and live comfortably.

[-Nobody- 519]

She has three boutiques, but she might not be rich from em. She could be using her money from one boutique to open another boutique, then another, and so forth.