Igros Moshe (Y.D. 2:130):
Concerning a giyores whose non-Jewish mother is sick. Should she go to her mother with her children as her mother requests?
Concerning the matter of a giyores who has been following the appropriate Jewish practices and has kept a distance from her father and mother from the time that she has converted 20 years ago even though they live in the same city. But now her mother has fallen ill and requests that she come with her children to see her because she has a great longing to see her grandchildren . Even though the giyores knows that according to the Torah there is relationship anymore with her parents, nevertheless she wants to know if it is appropriate because she has a very strong natural love to her parents and she wants to fulfill her mother's request at this time of sickness. Her rabbi wants to permit it because of the concern that she might revert to her old ways as we see that there is such a concern regarding inheritance that a decree was made that a convert inherits his non-Jewish father because of this fear (Kiddushin 17).
Answer: I agree that the halacha is as her rabbi wrote that it can be permitted but because of logic. Because it is not clear that this fear for other things can be compared to loss of money because the desire for them is not so strong. However the more appropriate reason is that they might say that the laws of Torah are not correct if she is told not to go and this is a very significant point by itself even without the concern that she might revert. We see this from the fact that the halacha is that we visit sick non-Jews for the sake of peace as well as sustain the poor non-Jews and bury their dead for the sake of peace (Gittin 61).... So it is obvious that she and her children would be going against the ways of peace of they don't visit her mother. So besides that factor the Rambam (Mamrim 5;11) states that it is prohibited for a ger to curse his non-Jewish father or hit him and not to shame him so that people won't say that the ger went from a higher religion to a lower one so he should at least not shame his father (Shulchan Aruch Y.D. 241)... So if she doesn't go to visit her sick mother with her children it will cause the mother suffering and maybe it will drive her crazy. Thus we see it is an insult to the mother if she doesn't go and it is such pain that it is like hitting and cursing her. So therefore going to her mother is not only permitted but is obligatory to comply with the wishes of her mother to come and bring her children....
R' Akiva Eiger writes that this is part of human culture.... This mean that even though it is not an explict law of the Torah that a non-Jew must honor his parents and therefore it is not an issue of coming from a higher religion to a low one nevertheless but since natural ethics requires honoring parents then it is also included in coming from a higher religion to a lower one. It is like the reason of chillul hashem if they should say that the Torah permits something that even a nonJewish knows is prohibited...
Therefore it appears in my opinion that it is like the prohibition against ingratitude that we find in agadata that G-d was very particular about this with Adam and also with the Jewish people. Therefore this is something prohibited which is the same between Jews and non-Jews... This is like we don't find explicit prohibitions on bad character traits even though they are disgusting and they incur punishment both for Jews and non-Jews....
We can conclude from this analysis that even if her mother wasn't sick it would be appropriate to go at infrequent occassions if it would appear as ingratitute if she didn't go. It is only to be with her parents on a regular basis that is prohibited even for her in order that she distance herself from them and not revert and it is surely prohibited for her children to go regularly because they might eat unkosher food. However now that her mother is sick -besides visiting for the sake of peace she is obligated to visit with her children to give some sort of honor to her mother and to avoid shaming her (Shulchan Aruch)
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