Should I claim the number of allowances on my W4 that the worksheet dictates? Single mom, new baby, one job, etc and my allowances per the W4 worksheet is 7.

[Hal_Al]

Yes. Unless you have a specific reasons for not doing so.

Doing so will reduce excess withholding and give you more take home pay. But, you still will not owe at tax time.

[SweetieJean]

"But, you still will not owe at tax time."  I think @Hal_Al  means "you still MAY owe at tax."
This is all fluid right now, due to the impending 2018 tax law changes.

[SweetieJean]

Also see Paychecks here:
<a rel="nofollow" target="_blank" href="https://www.usatoday.com/story/news/politics/2017/12/18/how-soon-after-president-trump-signs-tax-bil...>

[SweetieJean]

Under the new tax law, there will no longer be any personal exemptions starting in 2018.