Are sentences still Grammatically Correct when nominative cases are omitted?

(Also known as subjective cases)

For example:

Samatha stared down at the broken shards, [her] eyes welling with tears.

In this sentence, would the nominative case of ‘her’ need to be added in order for the sentence to be correct?

Another example:

He glowered down at Samantha, who stood at a measly 5’1 height. Samatha felt squashed by the glare; [she] felt unable to breathe.

Is the latter part of the last sentence grammatically correct without the nominative case ‘she’?

I really want to drop these words so I can increase the pace of the scene I’m writing, but I’m unsure if it’s correct English to do so.

Thank you so much in advance!