Applejack technically sees her whole family tree as her family, them all taking care of and caring for eachother. However if you want to nitpick then only Snap Apple is part of Applejack's family, being her daughter and all.
AJ always saw herself having a lot of kids, but as she grew older she found that her priorities changed and having a huge kiddie swarm of her own didn't seem that important anymore. She simply just didn't have time for dating and such, and besides he right pony just never came trotting into her life. She's okay with that though, she still has her farm and her amazing daughter to keep her plenty busy.
The first stallion AJ ever had a semi-serious and long relationship with is Soarin, who also became the father of AJ's daughter.
Applejack and Soarin both actually wanted children yet perhaps they both jumped into it a bit too soon into their relationship. During AJ's pregnancy and for a year afterwards the two of them found themselves questioning their relationship. Soarin had his home high in the sky, planning his career as a wonderbolt, the farm life really wasn't his thing. And Applejack would never want to leave her family farm.
Once they realised that neither of them would give up their way of life they decided to end it on good terms, still staying friends (with certain benefits). After Snapple was born they shared joint custody of her, each parent getting to house their daughter every other week.
Snap Apple was fine with this setup. Never having had any memories of her parents living together anyway. She loves her parents equally but has more in common with her dad than with her mother, wanting to be a wonderbolt and not having as much interest in farm work.
AJ is frustrated about this and tries in vain to get Snapple more interested ut with no luck. Ultimately she supports her daughter in whatever she does.
Ever since Granny Smith's passing AJ has worn a picture of her in a pendant adorning a choker so to forever hold her close. Granny Smith died just a few days after Snapple was born, so she did get to see her great grandchild one time before moving on. AJ believes she only held on so long because of her stubborness to see the little filly atleast once, something that both sadden and warm her heart.