I'm pretty sure what ended up being implied was about being a mother FIGURE, not just being a mother; since that's what I get from that moment between Nozomi-san and Shino-chan in the end.
OTOH, that dreaded looks on Nozomi-san throughout this chapter... all those (implied mostly) terrible flashbacks with her own mother going by her mind...
ps. that older teacher must've misunderstood something...
pps. I pretty much laughed on Nozomi-san's expense this chapter.