Yes, probably — and it depends almost entirely on whether your phone is signed into an account your mom controls. If she set the phone up, knows the Apple ID or Google password, or installed parental controls, she can see a lot more than most teenagers expect.
The three routes that actually expose browsing history:
1. Account sync. Chrome history syncs to whatever Google account the browser is signed into; Safari history syncs through iCloud if the device shares an Apple ID or family group. If you are signed into her account, your history appears in her Chrome or in Google My Activity — the free, first-party view, and the one most parents use.
2. Parental controls she installed. Google Family Link on Android shows app-by-app activity and screen time and can report browsing through Chrome supervision; Apple Screen Time shows websites visited and time spent per site (Content & Privacy Restrictions can also block categories). Both are free and both are visible in Settings — check for a Family Link entry under Google settings, or Screen Time with a passcode you did not set.
3. The household network. Router DNS logs, a Pi-hole, or a managed Wi-Fi service can log domains. Your mobile carrier bill and most home ISP bills do not list individual URLs — that part of the scare story is usually false.
Where Ultimate Phone Spy fits: it is our own parental-control dashboard for Android, Windows and Mac — browser history, app activity and screen time in one place for a device a parent administers, with plans on our web history page. It does not support iPhone, and it is not a hidden backdoor: installation on the device is disclosed, and nothing here works remotely or by guessing someone's password. Using it on another adult's phone without consent is unlawful in most places — stalking statutes, the Wiretap Act in the US, GDPR in the EU — and that line does not move because the person is family.
The practical move either way: open Settings and look for Family Link, Screen Time, or a device-management profile. If one is there, the honest conversation beats incognito mode, because incognito hides nothing at the network or account level.