I'm reminded of the chapter where Yotsuba and Miura reduce the Ayase household to just total chaos, then we suddenly jump to these two relaxing on a beach enjoying the quiet.
There's some undertones here and there that can support that ship IMO. The older sister is definitely the free spirit of the family so she'd be the most likely to take the forbidden love route anyway :P The dad's friend has a crush on her but it's mostly played for comedy so it's not like shes ''matched'' with anyone.