the use of 's

[miniwave]

hi everybody,
can anyone tell me please
which of the following sentence is correct?
She has the same eyes as her sister.
She has the same eyes as her sister's. (does the 's stand for has or for is it the possessive 's?)
10x

[Casiopea]

Hello, miniwave.

Try,

[1] She has the same eyes as her sister [has]. <Nominal + Verb>
[2] Her eyes are as brown as her sister's [eyes]. <Nominal + Nominal>

Hope that helps.

[dihen]

Not about the use of "['s]", but can I say "She has the same eyes that her sister has." If I can, does it change the meaning?

[Casiopea]

They are different structures but they express the same thing:

[1] She has the same eyes as her sister has.
<comparative as...as>

[2] She has the same eyes (that) her sister has.
<relative clause modifying 'eyes'>

Note, words in brackets (...) are optional.