Wolf-
I will step in to point out that the comparison to Tisha B’av is not a good one. In this point, volvie is correct in saying that yiddin do not have a “singled out” day for demonstration of X. The closest we do have is Tisha B’av and the 3 Weeks. Chazal recognized that it would not be healthy for us to be in constant state of mourning throughout the year and therefore designated a small period of time during which to express mourning (and many hold that they also confined all future communal mourning to be observed during this period). They established a specific day (or weeks, as it were) only to limit our mourning to a healthy amount of time. The same could not be said for singling out one day over another for positive expression, such as kibbud av v’em.
That aside, I do agree with cherrybim who said that if your mother expects something on the day then that is your chiyyuv of kibbud em for the day 🙂
On the subject of Chazal/Science, it has already been established here over and over again that there are two camps. One camp, of the latter day yeshiva movement believes in the infallibility of Chazal in all matters of knowledge. The other camp believes (as expressed clearly by R’ Hirsch in the introduction to Horeb) that Chazal were experts in Torah and in addition were on par with science experts of their time (i.e. not infallible in that regard). Neither camp will be convinced to change its views since both obtained said view from their own halachic sources. In that, it is no different than the eruv debate, or the question of the kashrus of bugs in the water. Hence, the debate here is pointless.
Regarding medical treatments found in the gemara – we are expressly forbidden to use them these days (except for one – fish bone stuck) precisely because they may not work today. Again, why they may not work would be explained differently by the two camps.