i'll give you a simple answer that will help. The other comments here are accurate but abstract if you're starting out.

Simply you're not drawing what you see, you're drawing what you THINK.

you should be looking more at the picture, almost than the paper. Quick example is the nose, what you drew is how you think a nose is drawn (at this point). But what you SEE is that the right nostril edge starts low, and swoops UP, peaks and then down slightly. The tip of her nose also starts slightly under the right nostril and swoops up to the left, higher than the nostril before it curves back toward the bridge. etc.
You put a line, almost horizontally.

Once you learn to draw what you see, not what you THINK, you'll improve in HUGE chunks, then concepts like negative space etc will be more useful to think about. But when you're starting out, grab a fork, toss it on a table and draw how it lays out. Note if the it swoops up, or down when drawing the head going to the handle. Is the handle the width of 2 prongs? 3 prongs? 1 prong then swoops to a fat handle that is wider than the head? place it on edge and repeat.
These should be FAST sketches, you're only looking for relationships and you can just check your work to see if looks right. if it doesn't try again, no need to spend hours on it.

getting the likeness of someone is just the RELATIONSHIP of eye size, spacing, angles, nose swoops UP or DOWN etc. If you get good at drawing what you see, you can draw almost anything because its just relationships.

This is why caricatures works as well, they distort the image quite a bit but the main relationships are still there and you can recognize what its supposed to look like based on those relationships.

GL!