Translation:My grandmother and your grandfather.
A lenited sh is a "h" sound, like th. It's the only Irish consonant that doesn't have separate broad and slender pronunciations by the way.
I'd expect "hanwaaher" and "hanaher". The audio sounds ok to me (the buzzing sound on the "r" reflects the slender sound) - but the á could probably be a bit longer, seeing as it's got a fada!
The best thing is to look at the tips & notes, which you'll need to look at on a PC - they aren't available on the mobile app.
But there is also a very good site called Nualeargais, although it can get technical. http://nualeargais.ie/gnag/lenition.htm
Here are some others I know of: https://en.wiktionary.org/wiki/Appendix:Irish_mutations#Effects_of_lenition
No — eclipsis is before the first letter of a word (e.g. fear → bhfear), and lenition is after the first letter of a word (e.g. bean → bhean). Seanmháthair has internal lenition because it’s a compound word, and the lenition is done after the first letter of the second word that forms the compound word: sean- + máthair = seanmháthair.
The second part (and any subsequent parts, if present) lenites in most compound words; a couple of examples where they don’t lenite are bándearg (“pink”) and feoilséantóir (“vegetarian”). The first part of a compound word would mutate in the same situations that a non-compound word beginning with the same letter would.