yes and no. yes, a jew remains halakhically jewish even after conversions. but not necessarily for aliyah: esther's grand-children would not be regarded as jews under the law of return. they would have to undergo a hashava laYahadut, and then the consideration of whether or not they would be eligible for aliyah would be up to the ministry of interior (50/50 outcome). they would have to explain how and why they feel a connection to the jewish people, a need to "return," and bring in papers about esther's burial etc. and their link to her. so no, a jewish grandmother who converted is not a free card for aliyah.
Turkish prime minister to form interim government with at least 2 Kurdish ministers (AP)
from the article: S.Y. Agnon's relatives: The E. Jerusalem Nashashibis