1)
Why did she say "ha'Sha'alti"?
1.
Malbim: One who pressures his friend, sometimes the latter will give to him temporarily, so he will desist from him. I did not ask from you. You gave to me. It should be a lasting gift!
2)
What is the meaning of "Sashleh"?
1.
Rashi: It is to cause a person to err. Radak - the Targum of Shegagah is Shalu (e.g. Vayikra 4:2). Why do I want a son, if he will not live?!
3)
Had she told him "Lo Sashleh Osi"?
1.
Rashi: She said "Al Techazev b'Shifchasecha" (verse 16).
2.
Radak citing Targum Yonasan: I told you - if a viable son will be given to me, [fine]; if not, do not pain me!