I think the fundamentals for voice feminization will apply here - at least her voice sounds more attainable, so many girls just want to sound like Ariana Grande who has a voice that is extreme even for cis women to emulate (it is girly, higher in pitch, lighter, and smaller than most women’s voices).

Personally I found it distressing to compare my voice to cis voices, I always found that set me up for worse training - I know voice therapists will want to know voice goals and help you on that path, but I personally thought it was better to set more pragmatic and less emotionally laden goals - basically to pass on the phone and in person as a woman rather than to achieve a particular target voice.

Either way, recommendations are generally to start daily practice of vocal warmups: semi-occluded vocal tract exercises (SOVTEs) like blowing raspberries or into a straw, use a pitch detector and learn to produce a pitch (helps to have a digital piano app so you can listen carefully to the pitch and then learn to reproduce it), then try pitch sustains and slides from the bottom to the top of your pitch range. Over time you can develop capacity to produce higher pitches.

With pitch while talking, you just want to not fall too low, but for singing pitch matters much more, so that’s why I recommendation daily sustains and slides. By sustain I mean producing and singing a particular note for as long as possible, you sustain each note as much as you can. This strengthens the voice. Slides are going from one pitch and moving to another, maybe up and down a few notes, etc. You can even try sliding from your pitch ceiling to your floor. This helps with agility and the ability to change pitch without the voice cracking or breaking.

Regarding vocal feminization, here is a beginner’s guide:

Broadly the two main gendering qualities to a voice are weight and size. With voice training the general idea is to:

1. ear train: learn to recognize when you weight is heavy vs light, when size is large vs small

2. mimic and experiment: learn to produce voices that are different weights and sizes, and esp. how to balance those to produce a typical feminine voice (suitably light and small)

3. practice: just keep listening and recognizing when you’re slipping up and to adjust your voice back into the feminine range, over time and lots of persistent practice, this habituates and becomes your voice!

For exploring weight:

• https://www.youtube.com/watch?v=a0PpzrWsTUE
• https://clyp.it/nwreza0c

For size:

• https://clyp.it/jdquw5ac
• https://www.youtube.com/watch?v=BW8X2nXexQs (this video has some pedagogical flaws, but is still good for listening / experimenting to some extent)

For more about the balance of weight and size (called “fullness”):

• https://www.youtube.com/watch?v=uVJuUoypVHE
• https://clyp.it/hu53kin0

Videos to help guide expectations for beginners:

• on goals: https://www.youtube.com/watch?v=JYSxobwWypI
• on daily practice: https://www.youtube.com/watch?v=fylIX28mlyY

For beginners it can also be helpful to explore more achievable lower-pitch feminine voices:

• https://www.youtube.com/watch?v=5OyfNLWf3UM

To ear train, it’s commonly recommended to listen to and “play along” with Selene’s clips:

• https://selenearchive.github.io/

Note: as you experiment or do any voice training exercise, make sure to pay close attention to:

• how it sounds to you as you do it,
• how it sounds when you record it and play it back for yourself,
• how others report they hear it, and also
• how it feels (in your body) when you produce the different sounds, keeping mental note so you can reproduce the voice if you need.

Experiments to try:

• using a pitch detector, sing a note and chant a word while maintain the same pitch, and change resonance/size from dark/large to bright/small while keeping pitch the same
• using a pitch detector, keep pitch steady and practice going from a heavy to a light weight without changing pitch
• mimic a large voice, like Patrick from Spongebob, or the Giant from Jack in the Beanstalk
• mimic a small voice, like when you talk to a baby or a cute puppy or animal, or accessible overfull childish voices, like Ash Ketchum from Pokemon or Dexter from Dexter’s Lab
• mimic a heavy voice
• mimic a light voice
• try producing an underfull voice intentionally
• try producing an overfull voice intentionally
• try going from full masc to overfull
• from full masc to underfull
• from full masc to full fem
• from full fem back to full masc
• from underfull to full fem
• from overfull to full fem

EDIT: in case you are curious of how effective this vocal training can be, here is a clip of my voice from 6 months ago: https://vocaroo.com/1kSpmaG1Khj2

EDIT2: also, did some pitch detection and her singing in Song to the Siren & Tròdlabùndin seems to be between C4 and C5 - the higher end of those pitches might be hard for me to produce as strongly as needed for singing in a performance, but they are definitely within my pitch range and could be strengthened such that I can use them when singing, so maybe they are for you too?

You might try using a pitch detector and establishing what your current pitch range is. I can’t seem to produce a pitch much lower than G2, and my default pitch / baseline was at C3, so my voice is usually between C3 and C4. I just try to not let my pitch fall below E3, since that dips into to more masculine territory.