Why did she say "Shovenah" again?
Malbim: Even if you would want to wait for me to remarry, bear sons, and the sons will mature, there are two problems. (a) I am too old to marry. (b) You would need to wait until they mature.
Why did she say "Zakanti mi'Hyos l'Ish"?
Rashi: I am too old to marry and bear sons, and you would marry them. They would not be forbidden due to Eshes Achiv she'Lo Hayah b'Olamo (a boy born after his brother died without children - he is forbidden to his brother's wife, and may not do Yibum), for Yibum did not apply, for Machlon and Kilyon did not have Kidushin with Rus and Orpah; they were Nochriyos. They had not converted 1 ; now they came to convert - "Itach Nashuv l'Amech" (10). From now, we will be one nation.
In any case, Yibum applies only to paternal brothers. This could not occur, for Elimelech was dead! However, had they already converted, future sons of Na'ami would be forbidden due to Eshes Achiv me'Imo. Some say that Yibum did apply - refer to 4:2:1:1 and the note there, refer to 4:11:5:1 and the note there.
What is the meaning of "Ki Amarti Yesh Li Tikvah"?
Rashi: Even if my heart would tell me that there is hope for me to remarry and bear children.
Malbim: Even if I would be to a man, would I bear children? Normally, a woman who delayed 10 years without a husband does not give birth afterwards 1 ! There are two possibilities. If during the 10 years I hoped (planned) to remarry, this preserves fertility. Also refer to 1:12:4:2.
Yevamos 34b. Malbim - the Gemara asked from Bas Rav Chisda, and answered that since she planned to remarry, this preserved her fertility.
Why did she say "v'Gam Hayisi ha'Laylah l'Ish"?
Rashi: And further - even if I became pregnant tonight with males
Why did she say "v'Gam Yaladti Banim"?
Rashi: Or even if I already gave birth to males
