ahh sorry to hear of your loss, i hope your little girl picks up soon

going piggy dating with a rescue is a great idea, the recommended ones on here all give you support & advice aftercare. Also you know you will have a pregnancy free companion & that the piggy friend will either be neutered or definitely a girl. Most quick sell pet shops don't have a clue whether its a girl or boy they are selling you & dont even care as long as they sell you one, not worried if your current piggy could get pregnant due to the shops miss-sexing.
At least your girl sounds like she has company with the rabbit nearby, although i hope she's not in with the rabbit? Its not recommended to house them together as a rabbit can easily injure or kill a piggy inadvertently, also the diet requirements are different for both, mainly that a rabbit can produce its own vitamin C but a piggy cant which causes health problems
Good luck on your piggy dating & hopefully we'll have to pigtures to see of your furbaby & new friend soon

xx