I feel like the majority of my posts are boring parenting questions, because I'm a FTM who worries too much. Sorry  :-/ 
I know that it's normal toddler behavior to ignore toys and just want to get into everything else. My concern is that I wonder if DD is bored with the toys she has and if we need to get her some more age-appropriate toys... like maybe the stuff she has is geared towards younger babies. I'm fairly certain she would ignore any new toys after about 5 minutes as well, which is why I'm hesitant to buy her anything new (plus, we are really limited for space). Examples of toys she has: stacking cups, simple puzzles, baby dolls/stuffed animals, all different sorts of balls (including one that says numbers and letters), a Little People play set, the V-tech walker, a Noah's Ark shape sorter, a little piano, play cell phone, old remotes without batteries, tea set, and lots of books, among other things. Outside she has a garden bench/water table, swing, and a soccer ball. She mostly doesn't care about anything but the soccer ball, and usually just wants to walk around and try to run away from me. 
I guess what I'm asking is, do those sorts of things sound appropriate for an 18-month old? Are there any toys you would recommend that your kids love? She doesn't seem to be super interested in any of her toys for any length of time. I am probably worried about nothing, because her grandparents have tons of toys as well which I would think are toddler-appropriate, and she doesn't pay much attention to them either (her favorite thing seems to be ripping out every single piece to the play kitchen and dumping them all over the floor at DH's grandma's). It's probably just her age and personality. Share your ideas with me 
                   
                PCOS with long, irregular cycles
First round of Clomid in May 2012= BFP #1, DD born January 2013 
BFP #2 in January 2014, DS born September 2014
Re: Toddler toys
First round of Clomid in May 2012= BFP #1, DD born January 2013
BFP #2 in January 2014, DS born September 2014
Honestly, his favorite thing to do is play with the dogs/cats. Feeding them, petting them, trying to get them to play with his toys, and cuddling them. Toys get boring, animals are always fun.
First round of Clomid in May 2012= BFP #1, DD born January 2013
BFP #2 in January 2014, DS born September 2014
Dd for her toy kitchen at 18months, and it's still one of her favorite toys at 7yrs. We've bought different M&D wooden food stuffs and everything for the kitchen gets stored in the kitchen. It's so great. That might be a fun toy for your dd while you are cooking. She can be making dinner for her babies while you are feeding the new baby.
As fast as rotating, it might be worth it to pull some out of her toy box entirely for a couple of weeks. Even if she doesn't play with them daily, even seeing them will make them "old hat.". Removing them from her site entirely might inspire the new feeling again.
Good luck!
dd has two tents. She and DS love them, I hide it a lot though. DD makes me get in it all the time, which makes me feel got and smothered. And she gets mad when the dog gets in it and knocks it over. Other than that, the kids play in it all day.
Ahhh forgot about the new baby! I think its much more important to have room for them
DS is all about non-toys right now. His favorite thing right now is an old gift wrap cardboard tube. Other toy favorites are wooden stakable pieces, and bouncy balls.