took some time and maybe I'm overloading with too much information, but i did a redraw of the 3/4 and side view whilst showing the construction process. the method i used is based on the loomis method with some minor differences. i decided an approach to show an example of head angles that are correctly proportioned instead of pointing out all the mistakes because, I think that it would be more helpful to visually grasp and cross check what's wrong and that i might of also missed a mistake that flew over my head but is clearly seen in my example that you can pickup on.
first off and probably the hardest part is constructing the Loomis head properly, since this requires a pretty good understanding of 3d form without it looking off are weird. there are probably not much i can say about the initial contruction that isnt said better in a youtube video like the one proko made. But, one mistake that i commonly when people construct the head is that they tend to not make the head or sphere wide enough which tends to cramp up all the facial features. personally for me, i like to draw the cranium of the ball area of your skill more like an egg shape where the front likea circle, but the sides view more of an oval.
the next part would bet to start blocking out the facial features like the eyebrows, nose and mouth. this part can definitely look daunting to do but for me, i found that once i started to grasp the first part, that it didnt take as long for this since your 3d awareness would be much better at this point. One potential mistake that i would like to point out in your drawing since its present in all of the heads is that the position of the nose is too short length wise. having the nose positioned too short results in the bottom part having too much space and contribute to a bigger looking jaw. This in itself isn't that big of a problem, but when it comes to drawing girls it could look more masculine. Conversely for girls, positioning the nose lower would make the chin smaller and less masculine so it would be generally fine to do. For most average people, the position of the nose should be around the halfway point from the browbone to the chin. On a side note, the only time you would consistently see the nose position further up would be in babies or gigachad guys. However, a question that might contradict this is, if a shorter nose is undesirable then why does it look relatively fine in your nun's front view. While I'm not 100% sure, i have a pretty good idea why which i'll talk about after the whole process to not get side tracked
the last part is to finally draw the face and add some hair to make it look cool. When i looked over the sketch, i actually thought that your noses and mouths looked pretty fine. But, it was more so the eyes that looked the most odd, but only in the 3/4 one. foreshortening would definitely be almost unnoticeable given how close the two eyes are which you exaggerated quite a lot in yours. another thing that is off is the spacing of the eye. this is purely from my observation, but to make sure the eyes will look correct in almost every angle, the length of the largest eye should be able to snuggle in between both eyes. however, you are defiantly able to break this rule given the style is appropriate for it. an example of both cases would be helltaker are for cramped eyes, and grandblue fantasy for far apart eyes. thought for the most part, using this rule should work for most styles.
Now, back to the question about the nose length in the front angle that contradicts me saying the a short nose looks unappealing in females and average looking guys. The thing i suspect that makes it right in this case is because for a front view face, any accidental distortion like placing the nose in an odd area, or drawing the jaw weirdly may causes our eyes interpret the face to look like in a slightly different angle to compensate. In your case, the nose and mouth appear to be position more upwards then what should be idea. for me, my brain then clued in the rest and made the head look like she was facing slightly upwards, thus making the head actually viewed in a slight low angle.
here's an example i quickly drew up, which i drew in an anime style since it's a style Im most comfortable in and the quickest to draw up, but should work for this example
here i drew a front angle, and slightly low angle and a front angle again, but this time the nose and the mouth are shifted upwards. I also drew a ratio of the noses position which you can probably see better in a new tab. While slightly exaggerated, I hope that it shows the reason why your front angle looks fine, which is because you most likely didnt draw with a symmetry tool and those small human imperfection slowly accumulated and caused you to accidently draw the face that resembles the most like the middle one
anyways, this was longer then i expected, and i was planning to try to point out every mistake and also show examples of how the facial features would like in different angles, but i realised it would become a full blown tutorial. but if you still have questions on them i can follow it up, i just didnt want to make this post longer then it already is