My son in law's sister is having a big wedding. Have known her for many years. Should I feel bad if she does not invite us to the wedding?

I am currently in the middle of planing my wedding. My guest list is over 150 people already and thats just inviting family (Grandparents, Aunts, Uncles, Cousins, siblings, nieces, nephews) I honestly cant afford to invite anyone else even though Id really like to invite all my friends and coworkers. Finding a bigger venue would cost more money, plus paying for everyone to eat, and if you want to serve drinks thats also extra, then you have to pay to rent chairs for everyone, buy enough favors.... it gets expensive!

So in my opinion if you didnt get an invite it probably isnt because they didnt want you there. They would honestly probably love to have you share in their special day and just cant afford to. At least thats how it is for me. I already feel terrible about it and people keep asking why they werent invited already or if they can came and it makes me feel worse to have to tell them no.