One does not "need" any of the "things". Walkers can actually be very dangerous. I remember hearing about a baby who was near the stairwell, and the door had accidentally been left open. She was in her walker -- and she slid toward the stairs, fell down them onto the basement cement and cracked her skull. That said, they can also be entertaining and provide mobility a child didn't have before. But they aren't "necessary". They take up space. And I know many plenty of young adults who never even saw a walker until they were too old to be in one.
I definately enjoyed having a swing, although I initially said I'd never use one. More importantly, my infants enjoyed the swing and I enjoyed a bit of free time from the constant holding and carrying.
What your child needs include love, nourishment, gentleness and parents who include her in their lives and make room for her idiosyncracies as they develop. :-) She needs warmth and clothing, lots of hugs and smiles. She needs a carseat so she is protected in the speeding bullets we label cars. You would probably enjoy a stroller at some point. But for entertainment, a blanket on the floor and some activity in the room, a couple of toys, and she's all set. I like the crib gym things, so a child can lay on its back, reach up and play with what hangs down. We used ours when our babies sat in the carseat in the house as well.
Don't feel you have to spend money because there is so much cool baby "stuff" in the stores. Be wise and responsible because you are living on only one income now. Try to hunker down and be inclined to build a savings account if you can manage that with just one income. Having money in the bank will go a LONG way toward minimizing any crises that come along, making molehills out of mountains . . . Having a bunch of stuff is just that -- and it's generally clutter. Some of it is fun clutter, but most of it is unnecessary. People were having babies way before there were cribs built to contain them at night, way before there were playpens, port-a-cribs, crib gyms, walkers, strollers, etc. . . Most of them survived, built our country and perpetuated the race. :-)