Why did Petunia Dursley accept Harry at the beginning?

[pippin_999]

No: HPFGUIDX 99658

--- In HPforGrownups at yahoogroups.com, "mariofett1187" 
<Mariofett1187 at a...> wrote:
> Dumbledore explains to Harry at the end of OoTP the magic 
protecting  him at Privet Drive-but why did Petunia accept the 
baby on her doorstep, when she and Vernon wanted nothign to 
do with Lily's  family? <

Well, um, it isn't usually your sister's kid that gets left on the 
doorstep, is it. Worse, they've been keeping it secret that Petunia 
has a sister, so it's *really*  going to look bad if they drop the 
baby off at an orphanage--nobody's going to believe their story. If 
the kid was   Petunia's nephew,  why wouldn't she take him in?  
Everybody in the neighborhood would be whispering about 
Vernon's illegitimate son.

Pippin