What you say is not true I'm afraid. This is pretty obvious, as 'Lord of the thunderbolt' (meaning Indra) is a male deity, so how could one use it for a girl? The first part, 'Jasw-' is the Sanskrit Yasho-, meaning 'beauty, honour, worth; respectable person, object of honour' (this also occurs in the names 'Jaswant' (Yashwant) and 'Jashoda' (Yashoda) for example). The second part, 'indra' is not only a name, it also means 'best, excellent, the first, the chief (of any class of objects)' when used at the end of compounds, according to the dictionary of Monier Williams. So, JASWINDER (or Yashwindra) means 'foremost in virtue', not "Indra (or even 'Lord') of the thunderbolt".
Unfortunately, in the BtN database, too many names with 'indra' in them are read as if they refer to the deity Indra by name, which leads to a number of wrong meanings: JITENDRA m means 'greatest conqueror', not "conqueror of Indra" (which just happens to be the meaning of the name Indrajit). NAGENDRA m means 'Lord of the (supernatural snakes called) Nagas' (AKA Shesha Naga), not "snake of Indra". NARENDRA m means 'best of men', not "man of Indra". RAJENDRA m means 'lord of kings, emperor', not "Indra is the king". RAVINDRA m means Ravi + Indra, not "Indra is the sun". RUPINDER f means 'foremost in beauty', not "Indra is beauty". SURINDER m means 'Lord of the (class of deities called) Suras', not "Indra is god". (The Lord of the Suras is none other than Indra. At first glance it may seem strange that the word 'indra' could mean anything other than Indra when it occurs in a name of Indra, but there you have it).