DD is 19 months and currently has a very varied schedule:
Mon: with sitter
Tues: with my mom
Wed: with MIL
Thurs: with sitter
Fri: DH watches her
The sitter that she goes to is very convenient...she lives 2 miles from us and doesn't watch any other kids (although she has a 6yo who is in kindergarden). My concern is that DD is not with any other kids her own age, or at all really. I do have playdates with friends, etc., but thats it. DH and I have been considering a daycare program a couple days a week instead of the sitter even though it will cost more and is further away, but I think DD will greatly benefit. I would love opinions from other parents who work full-time on what they do and why. Thanks!

After 3 failed Clomid+TI cycles, DD was conceived with IUI#1
TTC #2
Clomid 50 mg + IUI#1 = BFP, m/c and D&C at 7w1d
Clomid 50mg + IUI#2 = BFN
Clomid 100mg + IUI#3 = BFN
Lupron + Follistim + IVF#1 = 11ER, 10M, 10F, ET of 1 expanded BBA 5-day blast, 2 Frosties. BFP! Beta 10/13 = 264! Beta 10/15 = 702! EDD 6/21/14
Re: Sitter vs Daycare?
Have you looked into an in-home daycare? That might be more cost effective and allow you to get her the extra socialization you're looking for.
We had the girls with my mom and sister (and my nephew) from 12 weeks-~7.5 months. At that point we moved them to an in-home daycare three days a week. Now one day a week I bring them to my mom's so my sister and nephew can see them (and to get him some socialization, he's only 5 months older), one day a week my mom comes to us, and three days a week we bring them to daycare. I think it's a perfect schedule because they get socialization from daycare but also spend time with my nephew and my mom.
BFP 3.8.16 EDD 11.20.16
We have a sitter who only keeps our DD, and we don't have any plans of moving her anywhere until 2.5 or 3.
I think social interaction will come with maturity and time and honestly, I love her being the only one right now where we don't have to worry about things that come with daycares or playschools.
However, when she does get 3, we do plan on doing something to get her ready for Pre-K/Kinder. I'm a teacher and there is a daycare on campus for 3 and ups. We will probably do that. Other than that though, I love the fact that my little girl is getting her every need met - it's as if I'm a stay at home mom! I wouldn't do anything different if I were a stay at home. We see other babies her age, etc. during weekends and such.
HTH!