There are strong hints actually, Ness´s mom has a frying pan (which was Ana´s weapon), sure, there are tons of frying pans, but considering she is holding one in her artwork, its as if it had some significance to her character...





Then, there is Pollyana, which was Ana´s theme in Mother





There is also the fact that she is 100% Ok with Ness going adventuring through the world, as if it was something usual for kids.





And then there is the 13 year old range thingy...But keep in mind at the end of Mother, Ninten´s dad calls him for something odd. Pheraps in this 2nd mision it involved some time travel or otherworldy incident, explaining the age difference.





Im not using this as proof, but rather as a possibility, while the theory isnt proven true, it cant be proven false either ways, it depends on what the person headcanons.





