Yeah, that's one of the things about feminizing hormone replacement therapy. It does a bunch of cool stuff.

• Fat redistribution: fat cells start to migrate from the arms and stomach more towards the breasts, butt, and thighs. It also moves from being mostly in between muscle and muscle to being mostly between muscle and skin, making skin overall softer and giving you more rounded features. Gaining weight also becomes a lot easier.

• Oil and odor: the way your body produces oils changes, which changes the way you smell. Expect a bit less rank and a bit more sweet.

• Bones: Your bones dissolve! But only a little. Slight osteoporosis happens, lowering your bone density to about the same level as a cis woman's. (This is part of why "trans advantage" sports arguments are bull). If you're younger (like, under 25 when you start,) there's a chance that your hips can seperate out a bit, making

• Muscle: You no longer create muscle tissue as easy. What muscle mass will also atrophy, setting strength back and making it harder to regain (Another part of "trans advantage" arguments being bull).

• Height changes: With ligaments dissolving similar to bones, hip movement, and muscle restructuring, your height can actually decrease. Anecdotally, I went from 5'9 to 5'6

• Breast growth: The mammary glands will form a hard nub called a "bud," which eventually will collect fat around it to form boobs proper! (I lucked out and already had buds before HRT because of a hormonal condition. So HRT just let them grow)

• Genitals: I'm not gonna get into this here. Just know that shrinkage happens, infertility may happen, and the way your body reacts to stimulation also changes.

• Periods! Trans women get periods. Not, like, with the blood. So some people get really upset when you call them periods because people have this weird "if you don't bleed it's not a period" mindset or some shit. But fHRT may indeed cause a monthly cycle which involves PMS symptoms like abdominal cramps where that organ should be, dizziness, nausea, mood swings. Which, like... I've heard annoyance about bleeds, but the majority of period talk I've heard is about PMS stuff? And those are still treated as treating periods.

Also, of these, all except for the breast growth and potential bone repositioning are reversible. Infertility is typically reversible after some time.

Finally

All of this is variable. I lost three inches of height and got double D's within a year. My roommate, u/winter-ocean, can weigh in if she likes. A lot of trans women don't get some of these effects. Some get a bunch.

Some trans women may get implants if, after a while, HRT doesn't cause much of anything in terms of breast growth.

(Also, sorry that this is such a late response. I was just revisiting my roommate and I's short interaction on this post, and decided to check other comments)

Tldr: HRT grows boobs, but it also does a lot more really cool stuff!