is it ever ok to hosts your own baby shower?

S
Baby girl is born on July. We wanted to have a baby shower may 6 when the snow should have melted and it will be much warmer. We want to do an open invite block party (I'm close to my neighbors) outdoors bbq thing. We want to invite everybody, not just my girl friends.  I know a lot of people and want to celebrate with them but I don't feel close enough to anyone for them to hosts my shower, espically since H is so involved and excited about it.
Can we throw our own party? 
Another issue:  My parents are visiting but leave in April.  We thought about doing the shower earlier but the snow wod probably not be melted so we can't do it outside and my mom whose from south east Asia doesn't understand the concept of a shower so doesn't feel like she's missing out. But she would enjoy it, I think.  Should we do it inside, earlier, limit the guest list?