You can invite whoever you'd like to your bachelorette party! Typically, anyone in your wedding party, and any close friends/family members who aren't in your wedding party, are usually invited. The only major rule is that whoever is invited to the bachelorette party must also be invited to the wedding.
I agree with Lisa! Whoever you like, as long as they're also invited to the wedding!
To mine (assuming it can be held with restrictions currently being in place where we live) I am hoping to invite my mother and mil, my sister and sisters in law, plus my closest friends and all the mutual female friends of ours that are invited to our wedding. It ends up being about 26 people or so.
I could equally have done just a weekend away with my very closest girlfriends, and may have to downsize to that number of people, depending on what local restrictions are in place.
Yes invite whomever you'd like to the bachelorette party (as long as they are invited to the wedding)! For mine I invited my bridesmaids and a couple friends (all of whom are also significant others of members of our bridal party). We all had a bunch of fun.